Low molecular weight dry powder polymer for use as paper-making dry strength agent

ABSTRACT

The invention provides an associative polymer, a powder, and a process for making a powder comprising, networking one or more associative polymer(s) and one or more optional surfactant(s) to form a wet gel, and forming a powder from the wet gel, wherein the associative polymer(s) have a weight average molecular weight of from about 10 kDa to about 2,000 kDa.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.62/348,400, filed Jun. 10, 2016, the disclosure of which is incorporatedby reference herein in its entirety.

BACKGROUND OF THE INVENTION

High molecular weight polymers (e.g., at least 2 million Daltons) arecommonly used in papermaking as retention and drainage aids to improvedewatering of the fiber slurry and the retention of fine particles inthe sheet. Polymers with relatively low molecular weight (e.g.,typically lower than 2 million Daltons) are also typically employed tohelp improve the strength of the sheet. Generally, in order to improvepaper sheet strength, strength aids are required in high dosages (e.g.,about 2-4 lbs active/ton of dry pulp). Addition of high dosages (i.e.,2-4 lbs active/ton of dry pulp) of high molecular weight polymersresults in high flocculation and a paper sheet product, which lacksuniformity. Thus, high molecular weight polymers are typically notutilized as strength aids.

Both high and low molecular weight polymers can be provided to thepapermaker as aqueous polymer solutions. However, solution basedpolymers have high costs associated with transportation, degradation dueto long-term storage instability, as well as costs associated with, andfacilities required for application to the paper machine. Powder-basedstrength aids have the capacity to improve such costs associated withtransportation and addition to the paper machine. Some high molecularweight polymers can be formed into dry powder via a process comprising,inter alia, forming a polymer wet gel, cutting the wet gel, granulatingthe cut wet gel, drying the granules, and grinding the dried granules.However, due to their relative insolubility, they require large makedownunits to obtain a solution-based polymer capable of being added to thepaper machine. Thus, there remains a need for a low molecular weightstrength aid powder for use in the papermaking process, which can beadded to the paper machine as a powder, or as a solid slurry. However,low molecular weight (e.g., 2 million Daltons or less) polymers cannotbe processed in the same fashion as high molecular weight polymers.Generally, the polymer wet gel of low molecular weight polymers is toosoft to cut and process. Therefore, conventional strength aids aretypically low molecular weight solution polymers.

One technique used to obtain a processable polymer wet gel out of lowmolecular weight polymers is to include permanent chemical cross-linkingin the polymer backbone. Unfortunately, the permanently cross-linked lowmolecular weight polymers transform into high molecular weight polymersdue to the crosslinking. In addition, the dry powder produced by thistechnique is typically insoluble in water, thereby rendering the powderuseless in the papermaking process.

BRIEF SUMMARY OF THE INVENTION

A process for making a powder comprising one or more associativelynetworked polymer(s) of low molecular weight is provided. The processcomprises networking one or more associative polymer(s) and one or moreoptional surfactants to form a wet gel, and forming a powder from thewet gel, wherein the associative polymer(s) have a weight averagemolecular weight of from about 10 kDa to about 2,000 kDa.

Additionally, a powder is provided. The powder comprises one or moreassociative polymer(s) comprising one or more associative monomerunit(s) and one or more additional monomer unit(s) selected from atleast one of a cationic monomer unit, an anionic monomer unit, anonionic monomer unit, a zwitterionic monomer unit, or a combinationthereof, and optionally one or more surfactant(s), wherein theassociative polymer(s) have a weight average molecular weight of fromabout 10 kDa to about 2,000 kDa.

Additionally, an associative polymer is provided. The associativepolymer comprises one or more associative monomer unit(s), one or moreadditional monomer unit(s), one or more monomer unit(s) derived from amonomer of Formula I, and optionally one or more piperidine-2,6-dioneunit(s), wherein the one or more piperidine-2,6-dione(s) are formed uponcyclization of an acrylamide nitrogen of the monomer unit derived from amonomer of Formula I on a carbonyl of the additional monomer unit,wherein the associative polymer has a weight average molecular weight offrom about 10 kDa to about 2,000 kDa.

The processes of the present disclosure provide an approach to forming apolymer wet gel, comprising low molecular weight polymers, capable ofbeing machine processed into powder. Generally, the resulting powder iswater dispersible in which the degree of solubility is dependent on thelevel of dilution and/or the presence of a surfactant. Typically, thepowder is dispersible in water, and thus, can be incorporated into thepapermaking process. In particular, the processes and compositionsdescribed herein utilize a networking technique that improves thestrength of the polymer wet gel and dissipates upon dilution with water.In addition, the powder comprising low molecular weight associativepolymer(s) provided by the processes provided herein, when utilized in apapermaking process, generates paper having strength properties similarto that of paper obtained using conventional solution strength aids.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exemplary ¹³C NMR spectrum of the associative polymerdescribed in Example 5.

FIG. 2 graphically depicts the results of Example 10.

FIG. 3 graphically depicts the results of Example 10.

FIG. 4 graphically depicts the results of Example 11.

DETAILED DESCRIPTION OF THE INVENTION

A process for making a powder is provided. The process comprises forminga wet gel comprising one or more associative polymer(s) and optionallyone or more surfactant(s), and forming a powder from the wet gel,wherein the associative polymer(s) have a weight average molecularweight of from about 10 kDa to about 2,000 kDa.

In some embodiments, the process comprises forming a wet gel comprisingone or more associative polymer(s) and optionally one or moresurfactant(s), cutting the wet gel to form granules, and converting thegranules to form a powder, wherein the associative polymer(s) have aweight average molecular weight of from about 10 kDa to about 2,000 kDa.

The powder comprises one or more associatively networked polymer(s). Forexample, the powder can comprise a plurality (e.g., at least two polymermolecules) of associatively networked polymer(s), wherein theassociatively networked polymers have the same molecular structure(i.e., one associatively networked polymer), or the powder can comprisea plurality of associatively networked polymers, wherein theassociatively networked polymers have varying molecular structures(i.e., more than one associatively networked polymer). The one or moreassociatively networked polymer(s) can be any suitable polymer. Forexample, the one or more associatively networked polymer(s) can behomopolymers, copolymers, terpolymers, or greater, or a combinationthereof. In certain embodiments, the one or more associatively networkedpolymer(s) are terpolymers.

The associatively networked polymer(s) can be cationic, anionic,amphoteric, non-ionic, or zwitterionic. In some embodiments, theassociatively networked polymer(s) are cationic. As used herein,“cationic” polymers refer to polymers containing cationic monomer unitsor a combination of cationic monomer units and non-ionic monomer units.In some embodiments, the associatively networked polymer(s) are anionic.As used herein, “anionic” polymers refer to polymers containing anionicmonomer units or a combination of anionic monomer units and non-ionicmonomer units. In some embodiments, the associatively networkedpolymer(s) are amphoteric. As used herein, “amphoteric” polymers referto polymers containing cationic monomer units and anionic monomer units,or cationic monomer units, anionic monomer units, and non-ionic monomerunits. In some embodiments, the associatively networked polymer(s) arenon-ionic. As used herein, “non-ionic” polymers refer to polymerscontaining non-ionic monomer units. In some embodiments, theassociatively networked polymer(s) are zwitterionic. As used herein,“zwitterionic” polymers refer to polymers containing zwitterionicmonomer units or a combination of zwitterionic monomer units andcationic monomer units, anionic monomer units, and/or non-ionic monomerunits.

The associatively networked polymer(s) can exist as any suitablestructure type. For example, the associatively networked polymer(s) canexist as alternating polymers, random polymers, block polymers, graftpolymers, linear polymers, branched polymers, cyclic polymers, or acombination thereof. The associatively networked polymer(s) can containa single monomer unit, or any suitable number of different monomerunits. For example, the associatively networked polymer(s) can contain 2different monomer units, 3 different monomer units, 4 different monomerunits, 5 different monomer units, or 6 different monomer units. Theassociatively networked polymer(s)′ monomer units can exist in anysuitable concentration and any suitable proportion.

In certain embodiments, the powder comprises one or more associativelynetworked polymer(s), wherein the associative polymer (i.e., absent ofnetworking) have a weight average molecular weight of from about 10 kDato about 2,000 kDa. The associatively networked polymer(s) can have aweight average molecular weight of about 2,000 kDa or less, for example,about 1,800 kDa or less, about 1,600 kDa or less, about 1,400 kDa orless, about 1,200 kDa or less, about 1,000 kDa or less, about 900 kDa,or less, about 800 kDa, or less, about 700 kDa or less, about 600 kDa orless, or about 500 kDa or less. Alternatively, or in addition, theassociatively networked polymer(s) can have a weight average molecularweight of about 10 kDa or more, for example, about 50 kDa or more, about100 kDa or more, about 200 kDa or more, about 300 kDa or more, or about400 kDa or more. Thus, the associatively networked polymer(s) can have aweight average molecular weight bounded by any two of the aforementionedendpoints. For example, the associatively networked polymer(s) can havea weight average molecular weight of from about 10 kDa to about 500 kDa,from about 50 kDa to about 500 kDa, from about 100 kDa to about 500 kDa,from about 200 kDa to about 500 kDa, from about 300 kDa to about 500kDa, from about 400 kDa to about 500 kDa, from about 400 kDa to about600 kDa, from about 400 kDa to about 700 kDa, from about 400 kDa toabout 800 kDa, from about 400 kDa to about 900 kDa, from about 400 kDato about 1,000 kDa, from about 400 kDa to about 1,200 kDa, from about400 kDa to about 1,400 kDa, from about 400 kDa to about 1,600 kDa, fromabout 400 kDa to about 1,800 kDa, from about 400 kDa to about 2,000 kDa,from about 200 kDa to about 2,000 kDa, from about 500 kDa to about 2,000kDa, or from about 800 kDa to about 2,000 kDa.

Weight average molecular weight can be determined by any suitabletechnique. While alternate techniques are envisioned, in someembodiments, the weight average molecular weight is determined usingsize exclusion chromatography (SEC) equipped with a set of TSKgel PWcolumns (TSKgel Guard+GMPW+GMPW+G1000PW), Tosoh Bioscience LLC,Cincinnati, Ohio) and a Waters 2414 (Waters Corporation, Milford, Mass.)refractive index detector or a DAWN HELEOS II multi-angle lightscattering (MALS) detector (Wyatt Technology, Santa Barbara, Calif.).Moreover, the weight average molecular weight is determined from eithercalibration with polyethylene oxide/polyethylene glycol standardsranging from 150-875,000 Daltons or directly using light scattering datawith known refractive index increment (“dn/dc”).

In certain embodiments, the weight average molecular weight isdetermined by hydrolysis of the associative polymer to remove thehydrolysable side chains and then further analyzed with size exclusionchromatography (SEC). The associative polymer can be hydrolyzed by anysuitable technique. For example, the associative polymer can behydrolyzed by treatment with a 0.1 wt. % solution of NaOH at pH 12 witha cage stirrer at 400 rpm for one hour. As used herein, “hydrolysableside chains” refer to any side chain on an associative monomer unit oran additional monomer unit that can be cleaved through hydrolysis.Without wishing to be bound to any particular theory, the associativepolymer, comprising an associative monomer unit, may need to behydrolyzed prior to size exclusion chromatography due to low recoveryrate from the column. Generally, hydrolysis of the associative polymerdoes not cleave the polymer backbone and preserves the degree ofpolymerization of the associative polymer.

In certain embodiments, the associative monomer unit does not contain ahydrolysable side chain. In embodiments where the associative monomerunit does not contain a hydrolysable side chain, the weight averagemolecular weight can be determined by analyzing a surrogate of theassociative polymer. For example, the weight average molecular weightcan be determined by synthesizing a polymer using the exact sameformulation in the absence of the associative monomer unit. Withoutwishing to be bound to any particular theory, the polymer synthesizedwith the same formulation maintains a similar degree of polymerizationand results in a weight average molecular weight similar to anassociative polymer wherein the associative monomer unit is present.

Illustrative embodiments of the associative polymer(s) generally includeone or more associative monomer unit(s) and one or more additionalmonomer unit(s). As used herein, “additional monomer unit” refers to anymonomer unit other than the associative monomer unit. In certainembodiments, the one or more additional monomer units are derived from awater-soluble monomer (e.g., acrylamide, diallyldimethylammoniumchloride (“DADMAC”), 2-(acryloyloxy)-N,N,N-trimethylethanaminiumchloride (“DMAEA.MCQ”), etc.). As used herein, “derived” when referringto a monomer unit, means that the monomer unit has substantially thesame structure of a monomer from which it was made, wherein the terminalolefin has been transformed during the process of polymerization. Insome embodiments, the associative polymer(s) include one or moreassociative monomer unit(s), a monomer unit derived from a monomer ofFormula I, and one or more additional monomer unit(s). In certainembodiments, the associative polymer(s) include an associative monomerunit, a monomer unit derived from a monomer of Formula I, and anadditional monomer unit.

In some embodiments, the one or more associative monomer unit(s), andthe one or more additional monomer unit(s) can be incorporated into theassociative polymer(s) using monomers, dimers, trimers, oligomers,adducts, or a combination thereof of the monomers structures from whichthey are derived. For example, the one or more associative monomerunit(s), or the one or more additional monomer unit(s) can exist as adimer, trimer, oligomer, or adduct prior to incorporation into theassociative polymer(s).

The associative polymer(s) can comprise any one or more suitableadditional monomer unit(s) selected from a cationic monomer unit, ananionic monomer unit, a nonionic monomer unit, a zwitterionic monomerunit, and a combination of two or more thereof. For example, theassociative polymer(s) can comprise a cationic monomer unit and ananionic monomer unit, an anionic monomer unit and a nonionic monomerunit, a cationic monomer unit and a nonionic monomer unit, or a cationicmonomer unit, an anionic monomer unit, and a nonionic monomer unit. Incertain embodiments, the associative polymer(s) comprise and/or furthercomprise a zwitterionic monomer unit. The associative polymer(s) can besynthesized by any suitable polymerization method. For example, theassociative polymer(s) can be made through free radical polymerization,addition polymerization, free radical addition polymerization, cationicaddition polymerization, anionic addition polymerization, emulsionpolymerization, solution polymerization, suspension polymerization,precipitation polymerization, or a combination thereof. In certainembodiments, polymerization occurs through free radical polymerization.

Thus, a suitable additional monomer unit can be derived from any one ormore suitable monomers capable of participating in free radicalpolymerization. For example, the associative polymer(s) can comprise oneor more additional monomer units derived from a monomer selected from amonomer of Formula I, 2-(dimethylamino)ethyl acrylate (“DMAEA”),2-(dimethylamino)ethyl methacrylate (“DMAEM”), 3-(dimethylamino)propylmethacrylamide (“DMAPMA”), 3-(dimethylamino)propyl acrylamide (“DMAPA”),3-methacrylamidopropyl-trimethyl-ammonium chloride (“MAPTAC”),3-acrylamidopropyl-trimethyl-ammonium chloride (“APTAC”), N-vinylpyrrolidone (“NVP”), N-vinyl acetamide, hydroxyethyl methacrylate,hydroxyethyl acrylate, diallyldimethylammonium chloride (“DADMAC”),diallylamine, vinylformamide,2-(acryloyloxy)-N,N,N-trimethylethanaminium chloride (“DMAEA.MCQ”),2-(methacryloyloxy)-N,N,N-trimethylethanaminium chloride (“DMAEM.MCQ”),N,N-dimethylaminoethyl acrylate benzyl chloride (“DMAEA.BCQ”),N,N-dimethylaminoethyl methacrylate benzyl chloride (“DMAEM.BCQ”),2-acrylamido-2-methylpropane sulfonic acid (“AMPS”),2-acrylamido-2-methylbutane sulfonic acid (“AMBS”),[2-methyl-2-[(1-oxo-2-propenyl)amino]propyl]-phosphonic acid,methacrylic acid, acrylic acid, salts thereof, and combinations thereof.

In some embodiments, the associative polymer(s) comprise a monomer unitderived from a monomer of Formula I:

wherein R₁ is H or C₁-C₄ alkyl (e.g., methyl, ethyl, n-propyl,iso-propyl, n-butyl, sec-butyl, or tert-butyl) and each R₂ isindependently H or an organic group. As used herein, the term “organicgroup” refers to an alkyl group, an aryl group, a fluoroalkyl group, ora fluoroaryl group. In certain embodiments, the monomer unit derivedfrom a monomer of Formula I is considered an additional monomer unit.

In certain embodiments of the substituent R₂, the organic group is aC₁-C₆ alkyl group (i.e., 1, 2, 3, 4, 5, or 6 carbon units in length). Insome embodiments, the C₁-C₆ alkyl group is saturated, unsaturated,branched, straight-chained, cyclic, or a combination thereof. Anexemplary list of C₁-C₆ alkyl groups is methyl, ethyl, n-propyl,iso-propyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, sec-pentyl,neo-pentyl, or hexyl. In certain embodiments, the C₁-C₆ alkyl group issubstituted with one or more alkyl substituents, aryl substituents,heteroatoms, or combinations thereof (e.g., benzyl, phenylethyl,phenylpropyl, etc.). In some embodiments, the C₁-C₆ alkyl group can be aC₁-C₆ heteroalkyl group (i.e., 1, 2, 3, 4, 5, or 6 carbon units inlength). As used herein, “heteroalkyl group” refers to a saturated orunsaturated, substituted or unsubstituted, straight-chained, branched,or cyclic aliphatic group that contains at least 1 heteroatom (e.g., O,S, N, and/or P) in the core of the molecule (i.e., the carbon backbone).

In certain embodiments of the substituent R₂, the organic group is anaryl group. The aryl group can be any substituted or unsubstituted arylor heteroaryl group, wherein the heteroaryl group is an aromatic 5- or6-membered monocyclic group that has at least one heteroatom (e.g., O,S, or N) in at least one of the rings. The heteroaryl group can containone or two oxygen or sulfur atoms and/or from one to four nitrogenatoms, provided that the total number of heteroatoms in the ring is fouror less and the ring has at least one carbon atom. Optionally, thenitrogen, oxygen, and sulfur atoms can be oxidized (i.e., has undergonea process of losing electrons), and the nitrogen atoms optionally can bequaternized. In some embodiments, the aryl compound is phenyl, pyrrolyl,furanyl, thiophenyl, pyridyl, isoxazolyl, oxazolyl, isothiazolyl,thiazolyl, imidazolyl, thiadiazolyl, tetrazolyl, triazolyl, oxadiazolyl,pyrazolyl, pyrazinyl, triazinyl, pyrimidinyl, or pyridazinyl.

In certain embodiments of the substituent R₂, the organic group is aC₁-C₆ fluoroalkyl group or a C₁-C₆ fluoroaryl group. As used herein, theterms “fluoroalkyl” and “fluoroaryl” refer to any alkyl group or arylgroup, respectively, with one or more fluorine atoms.

In certain embodiments, the monomer of Formula I is acrylamide ormethacrylamide.

The associative polymer(s) can comprise the one or more additionalmonomer unit(s) in any suitable concentration, so long as theassociative polymer(s) include a suitable portion of one or moreassociative monomer unit(s) as provided herein. The associativepolymer(s) can comprise a sum total of about 90 mol % or more of the oneor more additional monomer unit(s), for example, about 91 mol % or more,about 92 mol % or more, about 93 mol % or more, about 94 mol % or more,about 95 mol % or more, about 96 mol % or more, about 97 mol % or more,about 98 mol % or more, or about 99 mol % or more. Alternatively, or inaddition to, the associative polymer(s) can comprise a sum total ofabout 99.995 mol % or less of the one or more additional monomerunit(s), for example, about 99.99 mol % or less, about 99.9 mol % orless, about 99.75 mol % or less, about 99.5 mol % or less, about 99.4mol % or less, about 99.3 mol % or less, about 99.2 mol % or less, orabout 99.1 mol % or less. Thus, the associative polymer(s) can comprisethe one or more additional monomer unit(s) in a sum total concentrationbounded by any two of the aforementioned endpoints. The associativepolymer(s) can comprise a sum total from about 90 mol % to about 99.995mol % of the one or more additional monomer unit(s), for example, fromabout 91 mol % to about 99.995 mol %, from about 92 mol % to about99.995 mol %, from about 93 mol % to about 99.995 mol %, from about 94mol % to about 99.995 mol %, from about 95 mol % to about 99.995 mol %,from about 97 mol % to about 99.995 mol %, from about 98 mol % to about99.995 mol %, from about 99 mol % to about 99.995 mol %, from about 99mol % to about 99.99 mol %, from about 99 mol % to about 99.9 mol %,from about 99 mol % to about 99.75 mol %, from about 99 mol % to about99.5 mol %, from about 99 mol % to about 99.4 mol %, from about 99 mol %to about 99.3 mol %, from about 99 mol % to about 99.2 mol %, from about99 mol % to about 99.1 mol %, from about 99.5 mol % to about 99.99 mol%, from about 99.5 mol % to about 99.995 mol %, from about 99.75 mol %to about 99.99 mol %, or from about 99.75 mol % to about 99.995 mol %.

The associative polymer(s) can comprise one or more associative monomerunit(s) of any suitable type(s). As described herein, “associativemonomer unit” refers to any monomer unit capable of coordinating withitself, other associative monomer units, surfactants, or a combinationthereof. The coordination can occur through any suitable interaction.For example, the coordination can occur through ionic bonding, hydrogenbonding, hydrophobic interactions, dipolar interactions, Van der Waalsforces, or a combination of two or more such coordination types.

In some embodiments, the associative monomer unit is formed postpolymerization by attaching an associative moiety to a polymer. As usedherein, “associative moiety” refers to any pendant chemical structurecapable of coordinating with itself, other associative monomer units,surfactants, or a combination thereof. The coordination can occurthrough any suitable interaction. For example, the coordination canoccur through ionic bonding, hydrogen bonding, hydrophobic interactions,dipolar interactions, Van der Waals forces, or a combination of two ormore such coordination types. In some embodiments, the associativemoiety is attached directly to the terminal end of a polymer, attachedthrough a linker to the terminal end of a polymer, attached directly tothe polymer backbone, attached to the polymer backbone through a linker,or a combination thereof.

In certain embodiments, the one or more associative monomer unit(s) ofthe one or more associatively networked polymer(s) are structurallysimilar. As used herein, “structurally similar” means that theassociative monomer unit(s) have similar chemical functional groups. Insome embodiments, the associative monomer unit(s) each comprise at leastone hydroxyl substituent. In some embodiments, the associative monomerunit(s) each comprise at least one amine substituent. In someembodiments, the associative monomer unit(s) each comprise a polyetherchain. In some embodiments, the associative monomer unit(s) eachcomprise a polyether chain, wherein the length of the polyether chainsare separated by six carbon units or less (i.e., 6, 5, 4, 3, 2, 1, or0). For example, if an associative monomer unit has a polyether chainlength of 16 carbon units, then a structurally similar associativemonomer unit will have a polyether chain length from 10-22 carbon units(i.e., 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, or 22). Incertain embodiments, the polyether chains each comprise the same numberof carbon ether units. In some embodiments, the associative monomerunit(s) each comprise an alkyl chain. In some embodiments, theassociative monomer unit(s) each comprise alkyl chains, wherein thelength of the alkyl chains are separated by six carbon units or less(i.e., 6, 5, 4, 3, 2, 1, or 0). For example, if an associative monomerunit has an alkyl chain length of 16 carbon units, then a structurallysimilar associative monomer unit will have an alkyl chain length from10-22 carbon units (i.e., 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20,21, or 22). In certain embodiments, the alkyl chains each comprise thesame number of carbon units. In certain embodiments, the associativemonomer unit(s) are the same.

In certain embodiments, the one or more associative monomer unit(s) areincorporated into the polymer through polymerization with one or moreassociative monomer(s). Thus, the one or more associative monomerunit(s) can be derived from any one or more suitable associativemonomer(s) selected from a nonionic associative monomer, a cationicassociative monomer, an anionic associative monomer, a zwitterionicassociative monomer, and a combination thereof. The one or moreassociative monomer(s) are capable of participating in polymerization.In certain embodiments, the one or more associative monomer(s) comprisean unsaturated subunit (e.g., acrylate, acrylamide, etc.), separate fromthe associative moiety, capable of participating in free radicalpolymerization. Generally, the one or more associative monomer(s) areselected from an acrylate, an acrylamide, or a combination thereof.

In an embodiment, the associative monomer unit is a nonionic associativemonomer unit. Generally, the nonionic associative monomer unit isderived from an acrylate and/or an acrylamide monomer of Formula II:

wherein R₃ is H or C₁-C₁₀ alkyl (e.g., (CH₂)_(k)CH₃), wherein k is aninteger from 0 to 9 (i.e., 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9), X is O orNH, m, n, and o are independently integers from 0 to 100, wherein when(n+o)≤3, m is at least 7, each Y₁ and Y₂ are independently H or C₁-C₄alkyl (e.g., methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, ortert-butyl), and R₄ is H or a hydrophobic group. In some embodiments,“C₁-C₁₀ alkyl” refers to a branched C₁-C₁₀ alkyl group. In certainembodiments, each Y₁ and Y₂ is independently chosen to produce block orrandom copolymers of ethylene oxide (“EO”), propylene oxide (“PO”), or acombination thereof. In some embodiments, m, n, and o refer to anaverage (rounded to the nearest integer) chain length of the designatedsubunits (i.e., average carbon chain length or average EO/PO chainlength). As used herein, the term “hydrophobic group” refers to an alkylgroup, an aryl group, a fluoroalkyl group, or a fluoroaryl group.

In certain embodiments of the substituent R₄, the hydrophobic group is aC₁-C₃₂ alkyl group (i.e., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, or32 carbon units in length). In some embodiments, the C₁-C₃₂ alkyl groupis saturated, unsaturated, branched, straight-chained, cyclic, or acombination thereof. An exemplary list of C₁-C₃₂ alkyl groups is methyl,ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, tert-butyl, n-pentyl,sec-pentyl, neo-pentyl, hexyl, heptyl, octyl, nonyl, lauryl, stearyl,cetyl, behenyl, cyclopentyl, cyclohexyl, propenyl, 2-butenyl, 3-butenyl,2-pentenyl, 3-pentenyl, or 4-pentenyl. In certain embodiments, theC₁-C₃₂ alkyl carbon group is further substituted with one or more alkylsubstituents, aryl substituents, heteroatoms, or combinations thereof.In some embodiments, the C₁-C₃₂ alkyl group can be a C₁-C₃₂ heteroalkylgroup (i.e., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17,18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, or 32 carbonunits in length). As used herein, “heteroalkyl group” refers to asaturated or unsaturated, substituted or unsubstituted,straight-chained, branched, or cyclic aliphatic group that contains atleast 1 heteroatom (e.g., O, S, N, and/or P) in the core of the molecule(i.e., the carbon backbone).

As used herein, the term “substituted” means that one or more hydrogenson the designated atom or group are replaced with another group providedthat the designated atom's normal valence is not exceeded. For example,when the substituent is oxo (i.e., ═O), then two hydrogens on the carbonatom are replaced. Combinations of substituents are permissible providedthat the substitutions do not significantly adversely affect synthesisor use of the associative polymer.

In certain embodiments of the substituent R₄, the hydrophobic group isan aryl group. The aryl group can be any substituted or unsubstitutedaryl or heteroaryl group, wherein the heteroaryl group is an aromatic 5-or 6-membered monocyclic group, 9- or 10-membered bicyclic group, or an11- to 14-membered tricyclic group, which has at least one heteroatom(e.g., O, S, or N) in at least one of the rings. Each ring of theheteroaryl group containing a heteroatom can contain one or two oxygenor sulfur atoms and/or from one to four nitrogen atoms, provided thatthe total number of heteroatoms in each ring is four or less and eachring has at least one carbon atom. The fused rings completing thebicyclic and tricyclic groups may contain only carbon atoms and may besaturated, partially saturated, or unsaturated. The nitrogen, oxygen,and sulfur atoms optionally can be oxidized, and the nitrogen atomsoptionally can be quaternized. Heteroaryl groups that are bicyclic ortricyclic must include at least one fully aromatic ring, but the otherfused ring or rings can be aromatic or non-aromatic. In someembodiments, the aryl group is phenyl, naphthyl, pyrrolyl, isoindolyl,indolizinyl, indolyl, furanyl, benzofuranyl, benzothiophenyl,thiophenyl, pyridyl, acridinyl, naphthyridinyl, quinolinyl,isoquinolinyl, isoxazolyl, oxazolyl, benzoxazolyl, isothiazolyl,thiazolyl, benzthiazolyl, imidazolyl, thiadiazolyl, tetrazolyl,triazolyl, oxadiazolyl, benzimidazolyl, purinyl, pyrazolyl, pyrazinyl,pteridinyl, quinoxalinyl, phthalazinyl, quinazolinyl, triazinyl,phenazinyl, cinnolinyl, pyrimidinyl, or pyridazinyl.

In certain embodiments of the substituent R₄, the hydrophobic group is aC₁-C₃₂ fluoroalkyl group or a C₁-C₃₂ fluoroaryl group. As used herein,the terms “fluoroalkyl” and “fluoroaryl” refer to any alkyl group oraryl group, respectively, with one or more fluorine atoms.

In certain embodiments, the nonionic associative monomer unit is derivedfrom an acrylate monomer comprising an acrylate head group of FormulaIII:

wherein R₅ is —CH₂(CH₂)_(p)CH₃, R₃ is H or C₁-C₁₀ alkyl (e.g.,(CH₂)_(k)CH₃), wherein k is an integer from 0 to 9 (i.e., 0, 1, 2, 3, 4,5, 6, 7, 8, or 9)), and p is an integer from 3 to 100 (e.g., from 4 to50, from 6 to 50, from 8 to 50, from 10 to 50, from 12 to 50, from 16 to50, or from 18 to 50. In some embodiments, the acrylate monomer ofFormula III is a mixture of two or more such acrylates, such that theaverage (rounded to the nearest integer) value of p is an integer from 3to 100 (e.g., from 4 to 50, from 6 to 50, from 8 to 50, from 10 to 50,from 12 to 50, from 16 to 50, or from 18 to 50). In some embodiments,“C₁-C₁₀ alkyl” refers to a branched C₁-C₁₀ alkyl group. In certainembodiments, R₅ is a branched alkyl group from 3 to 100 carbon units inlength. Generally, the nonionic associative monomer is selected fromlaurylacrylate, cetylacrylate, stearylacrylate, behenylacrylate, or acombination thereof. In certain embodiments, the nonionic associativemonomer unit is laurylacrylate, i.e., R₃═H and p=10.

In certain embodiments, the nonionic associative monomer unit is derivedfrom an acrylate monomer comprising an acrylate head group of FormulaIV:

wherein R₃ is H or C₁-C₁₀ alkyl (e.g., (CH₂)_(k)CH₃), wherein k is aninteger from 0 to 9 (i.e., 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9), q is aninteger from 2 to 100 (e.g., from 4 to 50, from 6 to 50, from 8 to 50,from 10 to 50, from 12 to 50, from 16 to 50, from 18 to 50, from 16 to100, from 18 to 100, or from 50 to 100), r is an integer from 0 to 30(e.g., from 2 to 30, from 4 to 30, from 6 to 30, from 8 to 30, from 10to 30, from 12 to 30, from 16 to 30, from 18 to 30, from 20 to 30, from22 to 30, or from 24 to 30), and each Y is independently H or CH₃. Insome embodiments, “C₁-C₁₀ alkyl” refers to a branched C₁-C₁₀ alkylgroup. In certain embodiments, each Y is independently selected toproduce block or random copolymers of ethylene oxide (“EO”), propyleneoxide (“PO”), or a combination thereof. In some embodiments, theacrylate monomer of Formula IV is a mixture of two or more suchacrylates, such that the average (rounded to the nearest integer) valueof q is an integer from 2 to 100, (e.g., from 4 to 50, from 6 to 50,from 8 to 50, from 10 to 50, from 12 to 50, from 16 to 50, from 18 to50, from 16 to 100, from 18 to 100, or from 50 to 100), and the average(rounded to the nearest integer) value of r is an integer from 0 to 30(e.g., from 2 to 30, from 4 to 30, from 6 to 30, from 8 to 30, from 10to 30, from 12 to 30, from 16 to 30, from 18 to 30, from 20 to 30, from22 to 30, or from 24 to 30). In some embodiments, the acrylate monomerof Formula IV is lauryl polyethoxy (25) methacrylate, cetyl polyethoxy(25) methacrylate, stearyl polyethoxy (25) methacrylate, behenylpolyethoxy (25) methacrylate, or a combination thereof. In certainembodiments, the nonionic associative monomer unit is a VISIOMER® ethermethacrylate commercially available from Evonik Industries (Essen,Germany). In some embodiments, the nonionic associative monomer unit iscetyl and/or stearyl polyethoxy (25) methacrylic ester, marketed underthe product name methacrylic ester (25 EO) C16-C18 fatty alcohol(“C18PEG1105MA”), commercially available from Evonik Industries (Essen,Germany).

In certain embodiments, the nonionic associative monomer unit is derivedfrom an acrylate monomer comprising an acrylate head group of Formula V:

wherein R₃ is H or C₁-C₁₀ alkyl (e.g., (CH₂)_(k)CH₃), wherein k is aninteger from 0 to 9 (i.e., 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9), each Y₁ andY₂ are independently H or C₁-C₄ alkyl (e.g., methyl, ethyl, n-propyl,iso-propyl, n-butyl, sec-butyl, or tert-butyl), and n and o areindependently integers ranging from 0 to about 100 (e.g., from about 0to about 90, from about 0 to about 80, from about 0 to about 70, fromabout 0 to about 60, from about 0 to about 50, from about 10 to about100, or from about 10 to about 50), R₄′ is C₈-C₃₀ alkyl group (i.e., 8,9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26,27, 28, 29, or 30 carbon units in length), wherein n and o cannot bothbe 0. In some embodiments, “C₁-C₁₀ alkyl” refers to a branched C₁-C₁₀alkyl group. In certain embodiments, each Y₁ and Y₂ are independentlyselected to produce block or random copolymers of ethylene oxide (“EO”),propylene oxide (“PO”), or a combination thereof. In some embodiments,the acrylate monomer of Formula V is a mixture of two or more suchacrylates, such that the average (rounded to the nearest integer) valuesof n and o are independently integers from 0 to 100, (e.g., from 0 to50, from 6 to 50, from 8 to 50, from 10 to 50, from 12 to 50, from 16 to50, from 18 to 50, from 16 to 100, from 18 to 100, or from 50 to 100).In certain embodiments, the acrylate monomer of Formula V contains aside chain derived from a Plurafac® surfactant, commercially availablefrom BASF Corporation (Florham Park, N.J.).

In another embodiment, the associative monomer unit is a cationicassociative monomer unit. Generally, the cationic associative monomerunit is derived from an acrylate salt monomer and/or an acrylamide saltmonomer of Formula VI:

wherein R₆ and R₇ are each independently H or C₁-C₁₀ to alkyl (e.g.,(CH₂)_(t)CH₃) wherein t is an integer from 0 to 9 (i.e., 0, 1, 2, 3, 4,5, 6, 7, 8, or 9), X is O or NH, s is an integer from 0 to 20 (e.g.,from 2 to 20, from 4 to 20, from 6 to 20, from 8 to 20, from 5 to 10,from 10 to 20, from 5 to 15, from 12 to 20, from 0 to 10, from 0 to 8,from 0 to 6, or from 0 to 4), Z is any anion, and R₈ is a hydrophobicgroup. In some embodiments, the acrylate and/or acrylamide salt ofFormula VI is a mixture of two or more such acrylates and/oracrylamides, such that the average (rounded to the nearest integer)value of s is an integer from 0 to 20 (e.g., from 2 to 20, from 4 to 20,from 6 to 20, from 8 to 20, from 5 to 10, from 10 to 20, from 5 to 15,from 12 to 20, from 0 to 10, from 0 to 8, from 0 to 6, or from 0 to 4).In some embodiments, “C₁-C₁₀ alkyl” refers to a branched C₁-C₁₀ alkylgroup. As used herein, the term “hydrophobic group” refers to an alkylgroup, an aryl group, a fluoroalkyl group, or a fluoroaryl group.

In certain embodiments of the substituent R₈, the hydrophobic group is aC₁-C₃₂ alkyl group (i.e., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, or32 carbon units in length). In some embodiments, the C₁-C₃₂ alkyl groupis saturated, unsaturated, branched, straight-chained, cyclic, or acombination thereof. An exemplary list of C₁-C₃₂ alkyl groups is methyl,ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, tert-butyl, n-pentyl,sec-pentyl, neo-pentyl, hexyl, heptyl, octyl, nonyl, lauryl, stearyl,cetyl, behenyl, cyclopentyl, cyclohexyl, propenyl, 2-butenyl, 3-butenyl,2-pentenyl, 3-pentenyl, or 4-pentenyl. In certain embodiments, theC₁-C₃₂ alkyl group is further substituted with one or more alkylsubstituents, aryl substituents, heteroatoms, or combinations thereof.In some embodiments, the C₁-C₃₂ alkyl group can be a C₁-C₃₂ heteroalkylgroup (i.e., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17,18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, or 32 carbonunits in length). As used herein, “heteroalkyl group” refers to asaturated or unsaturated, substituted or unsubstituted,straight-chained, branched, or cyclic aliphatic chain that contains atleast 1 heteroatom (e.g., O, S, N, and/or P) in the core of the molecule(i.e., the carbon backbone).

In certain embodiments of the substituent R₈, the hydrophobic group isan aryl group. The aryl group can be any substituted or unsubstitutedaryl or heteroaryl group, wherein the heteroaryl group is an aromatic 5-or 6-membered monocyclic group, 9- or 10-membered bicyclic group, and11- to 14-membered tricyclic group, which has at least one heteroatom(e.g., O, S, or N) in at least one of the rings. Each ring of theheteroaryl group containing a heteroatom can contain one or two oxygenor sulfur atoms and/or from one to four nitrogen atoms, provided thatthe total number of heteroatoms in each ring is four or less and eachring has at least one carbon atom. The fused rings completing thebicyclic and tricyclic groups may contain only carbon atoms and may besaturated, partially saturated, or unsaturated. The nitrogen, oxygen,and sulfur atoms optionally can be oxidized, and the nitrogen atomsoptionally can be quaternized. Heteroaryl groups that are bicyclic ortricyclic must include at least one fully aromatic ring, but the otherfused ring or rings can be aromatic or non-aromatic. In someembodiments, the aryl compound is phenyl, naphthyl, pyrrolyl,isoindolyl, indolizinyl, indolyl, furanyl, benzofuranyl,benzothiophenyl, thiophenyl, pyridyl, acridinyl, naphthyridinyl,quinolinyl, isoquinolinyl, isoxazolyl, oxazolyl, benzoxazolyl,isothiazolyl, thiazolyl, benzthiazolyl, imidazolyl, thiadiazolyl,tetrazolyl, triazolyl, oxadiazolyl, benzimidazolyl, purinyl, pyrazolyl,pyrazinyl, pteridinyl, quinoxalinyl, phthalazinyl, quinazolinyl,triazinyl, phenazinyl, cinnolinyl, pyrimidinyl, or pyridazinyl.

In certain embodiments of the substituent R₈, the hydrophobic group is aC₁-C₃₂ fluoroalkyl group or a C₁-C₃₂ fluoroaryl group. As used herein,the terms “fluoroalkyl” and “fluoroaryl” refer to any alkyl group oraryl group, respectively, with one or more fluorine atoms.

The ammonium salt of Formula VI can have any suitable anion counter ion(i.e., “Z”). In some embodiments, the anion counter ion (“Z”) comprisesan element selected from a halogen (e.g., fluoride, chloride, bromide,or iodide), sulfur, carbon, nitrogen, phosphorous, and a combinationthereof. An exemplary list of anions comprises fluoride, chloride,bromide, iodide, sulfide, sulfite, sulfate, sulfonated, bisulfate,bisulfite, thiosulfate, carbonate, bicarbonate, nitrate, nitrite,phosphate, hydrogen phosphate, dihydrogen phosphate, phosphite, hydrogenphosphite, dihydrogen phosphite, hexafluorophosphate, carboxylate,acetate, mesylate, tosylate, or triflate. In certain embodiments, Z isselected from fluoride, chloride, bromide, mesylate, tosylate, or acombination thereof.

In certain embodiments, the cationic associative monomer unit is derivedfrom an acrylamide salt monomer of Formula VII:

wherein R₆ is H or C₁-C₁₀ alkyl (e.g., (CH₂)_(t)CH₃) wherein t is aninteger from 0 to 9 (i.e., 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9), and u is aninteger from 0 to 30 (e.g., from 2 to 30, from 4 to 30, from 6 to 30,from 8 to 30, from 5 to 25, from 10 to 30, from 12 to 30, from 15 to 25,from 16 to 30, from 18 to 30, from 20 to 30, from 22 to 30, or from 24to 30). In some embodiments, “C₁-C₁₀ alkyl” refers to a branched C₁-C₁₀alkyl group. In some embodiments, the acrylamide salt of Formula VII isa mixture of two or more such acrylamides, such that the average(rounded to the nearest integer) value of u is an integer from 0 to 30(e.g., from 2 to 30, from 4 to 30, from 6 to 30, from 8 to 30, from 5 to25, from 10 to 30, from 12 to 30, from 15 to 25, from 16 to 30, from 18to 30, from 20 to 30, from 22 to 30, or from 24 to 30). In certainembodiments, the acrylamide salt of Formula VII is “MAPTAC-C12derivative” (i.e., where R₆ is CH₃ and u is 10).

In another embodiment, the associative monomer unit is an anionicassociative monomer unit. Generally, the anionic associative monomerunit is derived from an acrylate and/or an acrylamide monomer of FormulaVIII:

wherein R₉ is H or C₁-C₁₀ alkyl (e.g., (CH₂)_(v)CH₃) wherein v is aninteger from 0 to 9 (i.e., 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9), X is O orNH, M is any cation, and each R₁₀ is independently H or a hydrophobicgroup. In some embodiments, “C₁-C₁₀ alkyl” refers to a branched C₁-C₁₀alkyl group. As used herein, the term “hydrophobic group” refers to analkyl group, an aryl group, a fluoroalkyl group, or a fluoroaryl group.

In certain embodiments of the substituent R₁₀, the hydrophobic group isa C₁-C₃₂ alkyl group (i.e., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13,14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31,or 32 carbon units in length). In some embodiments, the C₁-C₃₂ alkylgroup is saturated, unsaturated, branched, straight-chained, cyclic, ora combination thereof. An exemplary list of C₁-C₃₂ alkyl groups ismethyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, tert-butyl,n-pentyl, sec-pentyl, neo-pentyl, hexyl, heptyl, octyl, nonyl, lauryl,stearyl, cetyl, behenyl, cyclopentyl, cyclohexyl, propenyl, 2-butenyl,3-butenyl, 2-pentenyl, 3-pentenyl, or 4-pentenyl. In certainembodiments, the C₁-C₃₂ alkyl group is further substituted with one ormore alkyl substituents, aryl substituents, heteroatoms, or combinationsthereof. In some embodiments, the C₁-C₃₂ alkyl group can be a C₁-C₃₂heteroalkyl group (i.e., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, or32 carbon units in length). As used herein, “heteroalkyl group” refersto a saturated or unsaturated, substituted or unsubstituted,straight-chained, branched, or cyclic aliphatic group that contains atleast 1 heteroatom (e.g., O, S, N, and/or P) in the core of the molecule(i.e., the carbon backbone).

In certain embodiments of the substituent R₁₀, the hydrophobic group isan aryl group. The aryl group can be any substituted or unsubstitutedaryl or heteroaryl group, wherein the heteroaryl group is an aromatic 5-or 6-membered monocyclic group, 9- or 10-membered bicyclic group, and11- to 14-membered tricyclic group, which has at least one heteroatom(e.g., O, S, or N) in at least one of the rings. Each ring of theheteroaryl group containing a heteroatom can contain one or two oxygenor sulfur atoms and/or from one to four nitrogen atoms, provided thatthe total number of heteroatoms in each ring is four or less and eachring has at least one carbon atom. The fused rings completing thebicyclic and tricyclic groups may contain only carbon atoms and may besaturated, partially saturated, or unsaturated. The nitrogen, oxygen,and sulfur atoms optionally can be oxidized, and the nitrogen atomsoptionally can be quaternized. Heteroaryl groups that are bicyclic ortricyclic must include at least one fully aromatic ring, but the otherfused ring or rings can be aromatic or non-aromatic. In someembodiments, the aryl compound is phenyl, naphthyl, pyrrolyl,isoindolyl, indolizinyl, indolyl, furanyl, benzofuranyl,benzothiophenyl, thiophenyl, pyridyl, acridinyl, naphthyridinyl,quinolinyl, isoquinolinyl, isoxazolyl, oxazolyl, benzoxazolyl,isothiazolyl, thiazolyl, benzthiazolyl, imidazolyl, thiadiazolyl,tetrazolyl, triazolyl, oxadiazolyl, benzimidazolyl, purinyl, pyrazolyl,pyrazinyl, pteridinyl, quinoxalinyl, phthalazinyl, quinazolinyl,triazinyl, phenazinyl, cinnolinyl, pyrimidinyl, or pyridazinyl.

In certain embodiments of the substituent R₁₀, the hydrophobic group isa C₁-C₃₂ fluoroalkyl group or a C₁-C₃₂ fluoroaryl group. As used herein,the terms “fluoroalkyl” and “fluoroaryl” refer to any alkyl group oraryl group, respectively, with one or more fluorine atoms.

The sulfonate salt can have any suitable cation counter ion (i.e., “M”).For example, the cation counter ion (“M”) can be a proton, ammonium, aquaternary amine, a cation of an alkali metal, a cation of an alkalineearth metal, a cation of a transition metal, a cation of a rare-earthmetal, a main group element cation, or a combination thereof. In someembodiments, the cation counter ion is a proton or a cation of lithium,sodium, potassium, magnesium, calcium, manganese, iron, zinc, or acombination thereof. In certain embodiments, M is selected fromhydrogen, lithium, sodium, potassium, or a combination thereof.

The one or more associative monomer unit(s) can be present in theassociative polymer in any suitable amount. The associative polymer cancomprise a sum total of about 10 mol % or less of the one or moreassociative monomer unit(s), for example, about 9 mol % or less, about 8mol % or less, about 7 mol % or less, about 6 mol % or less, about 5 mol% or less, about 4 mol % or less, about 3 mol % or less, about 2 mol %or less, or about 1 mol % or less. Alternatively, or in addition to, theassociative polymer can comprise about 0.005 mol % or more of the one ormore associative monomer unit(s), for example, about 0.01 mol % or more,about 0.1 mol % or more, about 0.25 mol % or more, about 0.3 mol % ormore, about 0.4 mol % or more, or about 0.5 mol % or more. Thus, theassociative polymer can comprise the one or more associative monomerunit(s) in a concentration bounded by any two of the aforementionedendpoints. The associative polymer can comprise from about 0.005 mol %to about 10 mol % of the one or more associative monomer unit(s), forexample, from about 0.005 mol % to about 9 mol %, from about 0.005 mol %to about 8 mol %, from about 0.005 mol % to about 7 mol %, from about0.005 mol % to about 6 mol %, from about 0.005 mol % to about 5 mol %,from about 0.005 mol % to about 4 mol %, from about 0.005 mol % to about3 mol %, from about 0.005 mol % to about 2 mol %, from about 0.005 mol %to about 1 mol %, from about 0.01 mol % to about 1 mol %, from about 0.1mol % to about 1 mol %, from about 0.25 mol % to about 1 mol %, fromabout 0.3 mol % to about 1 mol %, from about 0.4 mol % to about 1 mol %,from about 0.5 mol % to about 1.0 mol %, from about 0.01 mol % to about0.5 mol %, or from about 0.01 mol % to about 0.25 mol %.

In some embodiments, the associative polymer comprises an associativemonomer unit derived from a monomer of Formula II, a monomer unitderived from a monomer of Formula I, and an additional cationic monomerunit. In some embodiments, the associative polymer comprises anassociative monomer unit derived from a monomer of Formula II, a monomerunit derived from a monomer of Formula I, and an additional monomer unitderived from DMAEA.MCQ. In some embodiments, the associative polymercomprises an associative monomer unit derived from a monomer of FormulaII, an additional monomer unit derived from acrylamide, and anadditional monomer unit derived from DMAEA.MCQ. In certain embodiments,the associative polymer comprises an associative monomer unit derivedfrom VISIOMER® monomer C18PEG1105MA, an additional monomer unit derivedfrom acrylamide, and an additional monomer unit derived from DMAEA.MCQ.

In some embodiments, the associative polymer comprises an associativemonomer unit derived from a monomer of Formula II, a monomer unitderived from a monomer of Formula I, and an additional anionic monomerunit. In some embodiments, the associative polymer comprises anassociative monomer unit derived from a monomer of Formula II, a monomerunit derived from a monomer of Formula I, and an additional monomer unitderived from sodium acrylate. In some embodiments, the associativepolymer comprises an associative monomer unit derived from a monomer ofFormula II, an additional monomer unit derived from acrylamide, and anadditional monomer unit derived from sodium acrylate. In certainembodiments, the associative polymer comprises an associative monomerunit derived from VISIOMER® monomer C18PEG1105MA, an additional monomerunit derived from acrylamide, and an additional monomer unit derivedfrom sodium acrylate.

In some embodiments, the associative polymer comprises an associativemonomer unit derived from a monomer of Formula VI, a monomer unitderived from a monomer of Formula I, and an additional cationic monomerunit. In some embodiments, the associative polymer comprises anassociative monomer unit derived from a monomer of Formula VI, a monomerunit derived from a monomer of Formula I, and an additional monomer unitderived from DMAEA.MCQ. In some embodiments, the associative polymercomprises an associative monomer unit derived from a monomer of FormulaVI, an additional monomer unit derived from acrylamide, and anadditional monomer unit derived from DMAEA.MCQ. In certain embodiments,the associative polymer comprises an associative monomer unit derivedfrom MAPTAC-C12 derivative of Formula VII, an additional monomer unitderived from acrylamide, and an additional monomer unit derived fromDMAEA.MCQ.

In some embodiments, the associative polymer comprises an associativemonomer unit derived from a monomer of Formula VI, a monomer unitderived from a monomer of Formula I, and an additional anionic monomerunit. In some embodiments, the associative polymer comprises anassociative monomer unit derived from a monomer of Formula VI, a monomerunit derived from a monomer of Formula I, and an additional monomer unitderived from sodium acrylate. In some embodiments, the associativepolymer comprises an associative monomer unit derived from a monomer ofFormula VI, an additional monomer unit derived from acrylamide, and anadditional monomer unit derived from sodium acrylate. In certainembodiments, the associative polymer comprises an associative monomerunit derived from MAPTAC-C12 derivative of Formula VII, an additionalmonomer unit derived from acrylamide, and an additional monomer unitderived from sodium acrylate.

In some embodiments, the associative polymer comprises an associativemonomer unit derived from a monomer of Formula VIII, a monomer unitderived from a monomer of Formula I, and an additional cationic monomerunit. In some embodiments, the associative polymer comprises anassociative monomer unit derived from a monomer of Formula VIII, amonomer unit derived from a monomer of Formula I, and an additionalmonomer unit derived from DMAEA.MCQ.

In some embodiments, the associative polymer comprises an associativemonomer unit derived from a monomer of Formula VIII, a monomer unitderived from a monomer of Formula I, and an additional anionic monomerunit. In some embodiments, the associative polymer comprises anassociative monomer unit derived from a monomer of Formula VIII, amonomer unit derived from a monomer of Formula I, and an additionalmonomer unit derived from sodium acrylate.

Also provided is an associative polymer of Formula AP₁:

wherein E is one or more associative monomer unit(s), F is one or moreadditional monomer unit(s), G is one or more monomer unit(s) derivedfrom a monomer of Formula I, H is optionally present and is one or morepiperidine-2,6-dione unit(s), wherein the one or morepiperidine-2,6-dione(s) are formed upon cyclization of an acrylamidenitrogen of the monomer unit derived from the monomer of Formula I (“G”)on a carbonyl of the additional monomer unit (“F”), wherein theassociative polymer has a weight average molecular weight of from about10 kDa to about 2,000 kDa.

In some embodiments, the associative polymer is of formula AP₂:

wherein E is one or more associative monomer unit(s), E′ is a molepercentage value of from about 0.005 to about 10, F is one or moreadditional monomer unit(s), F′ is a mole percentage value of from about0.005 to about 90, G is one or more monomer unit(s) derived from amonomer of Formula I, and G′ is a mole percentage value of from about 10to about 99.99. Monomer unit E is defined by the associative monomerunits described herein. Monomer units F and G are defined by theadditional monomer units and monomer units derived from the monomer ofFormula I, respectively, described herein.

As described herein, the associative polymer of formula AP₂ can exist asan alternating polymer, random polymer, block polymer, graft polymer,linear polymer, branched polymer, cyclic polymer, or a combinationthereof. Thus, E, F, and G can exist in any suitable order (e.g., EGF,EFG, GEF, GFE, FEG, or FGE), including repeating individual units (e.g.,EEFFFGG, EFGGEFEE, EFGEEE, EEEEFG, etc.).

The amount of one or more associative monomer unit(s) (“E′”), and thesum total of one or more additional monomer unit(s) (“F′”+“G′”) are asdescribed previously for the one or more associative monomer unit(s) andthe sum total of one or more additional monomer unit(s).

In some embodiments, the associative polymer of formula AP₂ undergoescharge degradation to provide an associative polymer of formula AP₃:

wherein E is one or more associative monomer unit(s), E″ is a molepercentage value of from about 0.005 to about 10, F is one or moreadditional monomer unit(s), F″ is a mole percentage value of from about0.005 to about 90, G is one or more monomer unit(s) derived from amonomer of Formula I, G″ is a mole percentage value of from about 10 toabout 99.99, H is one or more piperidine-2,6-dione unit(s), wherein theone or more piperidine-2,6-dione(s) are formed upon cyclization of anacrylamide nitrogen of the monomer unit derived from a monomer ofFormula I (“G”) on a carbonyl of the additional monomer unit (“F”), andH″ is a mole percentage value of from about 0 (i.e., trace amounts) toabout 10. As used herein, “charge degradation” refers to the process ofa monomer unit derived from a monomer of Formula I cyclizing on acharged additional monomer unit (i.e., a cationic and/or anionic monomerunit), such that the charged substituent of the additional monomer unitis displaced, and thus, the polymer has less cationic monomer unitsand/or less anionic monomer units. Without wishing to be bound by anyparticular theory, it is believed that the charge degradation can occurspontaneously, or can be facilitated by one or more components in thepolymer solution.

In certain embodiments, the associative polymer is of formula AP₃:

wherein E is one or more associative monomer unit(s), E″ is a molepercentage value of from about 0.005 to about 10, F is one or moreadditional monomer unit(s), F″ is a mole percentage value of from about0.005 to about 90, G is one or more monomer unit(s) derived from amonomer of Formula I, G″ is a mole percentage value of from about 10 toabout 99.99, H is one or more units of the formula

wherein R₁ is H or C₁-C₄ alkyl (e.g., methyl, ethyl, n-propyl,iso-propyl, n-butyl, sec-butyl, or tert-butyl) and R₂ is H or an organicgroup, and H″ is a mole percentage value of from about 0 (i.e., traceamounts) to about 10. In certain embodiments, R₁ and R₂ are hydrogen.

As described herein, the associative polymer of formula AP₃ can exist asan alternating polymer, random polymer, block polymer, graft polymer,linear polymer, branched polymer, cyclic polymer, or a combinationthereof. Thus, E, F, G, and H can exist in any suitable order (e.g.,EGFH, EGHF, EHFG, EHGF, EFGH, EFHG, FEGH, FEHG, FHEG, FHGE, FGEH, FGHE,GHFE, GHEF, GEFH, GEHF, GFHE, GFEH, HEFG, HEGF, HGEF, HGFE, HFEG, orHFGE), including repeating individual units (e.g., EEFFFGGHHH,EFGGEFEEH, EFGEEEHH, HHHEEEEFG, etc.).

In certain embodiments, the associative polymer is of formula AP₄:

wherein each R₁ is independently H or C₁-C₄ alkyl (e.g., methyl, ethyl,n-propyl, iso-propyl, n-butyl, sec-butyl, or tert-butyl), each R₂ isindependently H or an organic group, R₃ is H or C₁-C₁₀ alkyl (e.g.,(CH₂)_(k)CH₃), wherein k is an integer from 0 to 9 (i.e., 0, 1, 2, 3, 4,5, 6, 7, 8, or 9), X is O or NH, m, n, and o are independently integersfrom 0 to 100, wherein when (n+o)≤3, m is at least 7, each Y₁ and Y₂ areindependently H or C₁-C₄ alkyl (e.g., methyl, ethyl, n-propyl,iso-propyl, n-butyl, sec-butyl, or tert-butyl), and R₄ is H or ahydrophobic group, E″ is a mole percentage value of from about 0.005 toabout 10, F is one or more additional monomer unit(s), F″ is a molepercentage value of from about 0.005 to about 90, G″ is a molepercentage value of from about 10 to about 99.99, and H″ is a molepercentage value of from about 0 (i.e., trace amounts) to about 10. Insome embodiments, “C₁-C₁₀ alkyl” refers to a branched C₁-C₁₀ alkylgroup.

In certain embodiments of the associative polymer of formula AP₄, F isderived from a diallyldimethylammonium chloride (“DADMAC”) monomer. Incertain embodiments of the associative polymer of formula AP₄, F isderived from a 2-(acryloyloxy)-N,N,N-trimethylethanaminium chloride(“DMAEA.MCQ”) monomer.

In certain embodiments, the associative polymer is of formula AP₅:

wherein each R₁ is independently H or C₁-C₄ alkyl (e.g., methyl, ethyl,n-propyl, iso-propyl, n-butyl, sec-butyl, or tert-butyl), each R₂ isindependently H or an organic group, R₃ is H or C₁-C₁₀ alkyl (e.g.,(CH₂)_(k)CH₃), wherein k is an integer from 0 to 9, q is an integer from2 to 100, r is an integer from 0 to 30, each Y is independently H orCH₃, E″ is a mole percentage value of from about 0.005 to about 10, F″is a mole percentage value of from about 0.005 to about 90, G″ is a molepercentage value of from about 10 to about 99.99, and H″ is a molepercentage value of from about 0 (i.e., trace amounts) to about 10. Insome embodiments, “C₁-C₁₀ alkyl” refers to a branched C₁-C₁₀ alkylgroup.

In certain embodiments, the associative polymer is of formula AP₆:

wherein r is an integer from 0 to 30 (e.g., from 2 to 30, from 4 to 30,from 6 to 30, from 8 to 30, from 10 to 30, from 12 to 30, from 16 to 30,from 18 to 30, from 20 to 30, from 22 to 30, or from 24 to 30), each Yis independently H or CH₃, E″ is a mole percentage value of from about0.005 to about 10, F″ is a mole percentage value of from about 0.005 toabout 90, G″ is a mole percentage value of from about 10 to about 99.99,and H″ is a mole percentage value of from about 0 (i.e., trace amounts)to about 10. In certain embodiments, r is an integer from 14 to 16.

In certain embodiments, the associative polymer is of formula AP₇:

wherein each R₁ is independently H or C₁-C₄ alkyl (e.g., methyl, ethyl,n-propyl, iso-propyl, n-butyl, sec-butyl, or tert-butyl), each R₂ isindependently H or an organic group, R₆ and R₇ are each independently Hor C₁-C₁₀ alkyl (e.g., (CH₂)_(t)CH₃) wherein t is an integer from 0 to9, X is O or NH, s is an integer from 0 to 20, Z is any anion, and R₈ isa hydrophobic group, E″ is a mole percentage value of from about 0.005to about 10, F is one or more additional monomer unit(s), F″ is a molepercentage value of from about 0.005 to about 90, G″ is a molepercentage value of from about 10 to about 99.99, and H″ is a molepercentage value of from about 0 (i.e., trace amounts) to about 10. Insome embodiments, “C₁-C₁₀ alkyl” refers to a branched C₁-C₁₀ alkylgroup.

In certain embodiments, the associative polymer is of formula AP₈:

wherein each R₁ is independently H or C₁-C₄ alkyl (e.g., methyl, ethyl,n-propyl, iso-propyl, n-butyl, sec-butyl, or tert-butyl), each R₂ isindependently H or an organic group, R₆ is H or C₁-C₁₀ alkyl (e.g.,(CH₂)_(t)CH₃) wherein t is an integer from 0 to 9, and u is an integerfrom 0 to 30, E″ is a mole percentage value of from about 0.005 to about10, F″ is a mole percentage value of from about 0.005 to about 90, G″ isa mole percentage value of from about 10 to about 99.99, and H″ is amole percentage value of from about 0 (i.e., trace amounts) to about 10.In some embodiments, “C₁-C₁₀ alkyl” refers to a branched C₁-C₁₀ alkylgroup.

In certain embodiments, the associative polymer is of formula AP₉:

wherein R₆ is H or C₁-C₁₀ alkyl (e.g., (CH₂)_(t)CH₃) wherein t is aninteger from 0 to 9, and u is an integer from 0 to 30, E″ is a molepercentage value of from about 0.005 to about 10, F″ is a molepercentage value of from about 0.005 to about 90, G″ is a molepercentage value of from about 10 to about 99.99, and H″ is a molepercentage value of from about 0 (i.e., trace amounts) to about 10. Insome embodiments, “C₁-C₁₀ alkyl” refers to a branched C₁-C₁₀ alkylgroup.

In certain embodiments of the associative polymers of formula AP₇₋₉(i.e., AP₇, AP₈, or AP₉), F is derived from one or more monomersselected from acrylic acid, methacrylic acid, or salts thereof.

In certain embodiments, the associative polymer is of formula AP₁₀:

wherein each R₁ is independently H or C₁-C₄ alkyl (e.g., methyl, ethyl,n-propyl, iso-propyl, n-butyl, sec-butyl, or tert-butyl), each R₂ isindependently H or an organic group, R₉ is H or C₁-C₁₀ alkyl (e.g.,(CH₂)_(v)CH₃) wherein v is an integer from 0 to 9, X is O or NH, M isany cation, and each R₁₀ is independently H or a hydrophobic group, E″is a mole percentage value of from about 0.005 to about 10, F is one ormore additional monomer unit(s), F″ is a mole percentage value of fromabout 0.005 to about 90, G″ is a mole percentage value of from about 10to about 99.99, and H″ is a mole percentage value of from about 0 (i.e.,trace amounts) to about 10. In some embodiments, “C₁-C₁₀ alkyl” refersto a branched C₁-C₁₀ alkyl group.

In certain embodiments, the associative polymer is of formula AP₁₁:

wherein R₉ is H or C₁-C₁₀ alkyl (e.g., (CH₂)_(v)CH₃) wherein v is aninteger from 0 to 9, X is O or NH, M is any cation, and each R₁₀ isindependently H or a hydrophobic group, E″ is a mole percentage value offrom about 0.005 to about 10, F is one or more additional monomerunit(s), F″ is a mole percentage value of from about 0.005 to about 90,G″ is a mole percentage value of from about 10 to about 99.99, and H″ isa mole percentage value of from about 0 (i.e., trace amounts) to about10. In some embodiments, “C₁-C₁₀ alkyl” refers to a branched C₁-C₁₀alkyl group.

As described herein, the associative polymers of formula AP₄-AP₁₁ (i.e.,AP₄, AP₅, AP₆, AP₇, AP₈, AP₉, AP₁₀, or AP₁₁) can exist as an alternatingpolymer, random polymer, block polymer, graft polymer, linear polymer,branched polymer, cyclic polymer, or a combination thereof. Thus, themonomer units can exist in any suitable order, including repeatingindividual units.

The presence of the monomer unit H can be detected by any suitablemethod. In some embodiments, monomer H is detected by ¹³CNMR, ¹H NMR, IRspectroscopy, or a combination thereof.

The abundance of the monomer unit H can be determined by any suitablemethod. In some embodiments, the abundance of the monomer unit H can bedetermined by relative comparison of the peak integrations of a ¹³CNMRspectrum, ¹HNMR spectrum, IR spectrum, or a combination thereof.

In some embodiments of the associative polymers of formula AP₃₋₁₁ (i.e.,AP₃, AP₄, AP₅, AP₆, AP₇, AP₈, AP₉, AP₁₀, or AP₁₁), E″ is from about0.005 mol % to about 10 mol % (e.g., from about 0.005 mol % to about 9mol %, from about 0.005 mol % to about 8 mol %, from about 0.005 mol %to about 7 mol %, from about 0.005 mol % to about 6 mol %, from about0.005 mol % to about 5 mol %, from about 0.005 mol % to about 4 mol %,from about 0.005 mol % to about 3 mol %, or from about 0.005 mol % toabout 2 mol %), F″ is from about 0.005 mol % to about 90 mol % (e.g.,from about 0.005 mol % to about 80 mol %, from about 0.005 mol % toabout 70 mol %, from about 0.005 mol % to about 60 mol %, from about0.005 mol % to about 50 mol %, from about 0.005 mol % to about 40 mol %,from about 0.005 mol % to about 35 mol %, from about 0.005 mol % toabout 30 mol %, from about 0.005 mol % to about 25 mol %, from about0.005 mol % to about 20 mol %, from about 0.005 mol % to about 16 mol %,from about 0.005 mol % to about 12 mol %, from about 0.005 mol % toabout 10 mol %, from about 2 mol % to about 20 mol %, from about 4 mol %to about 20 mol %, from about 6 mol % to about 20 mol %, from about 4mol % to about 16 mol %, from about 4 mol % to about 12 mol %, or fromabout 4 mol % to about 10 mol %), G″ is from about 10 mol % to about99.99 mol % (e.g., from about 10 mol % to about 99.99 mol %, from about20 mol % to about 99.99 mol %, from about 30 mol % to about 99.99 mol %,from about 40 mol % to about 99.99 mol %, from about 50 mol % to about99.99 mol %, from about 60 mol % to about 99.99 mol %, from about 70 mol% to about 99.99 mol %, from about 80 mol % to about 99.99 mol %, fromabout 80 mol % to about 99.95 mol %, from about 80 mol % to about 99.9mol %, from about 80 mol % to about 99.5 mol %, from about 80 mol % toabout 99 mol %, from about 80 mol % to about 97 mol %, from about 80 mol% to about 95 mol %, from about 80 mol % to about 92 mol %, from about80 mol % to about 90 mol %, from about 84 mol % to about 99 mol %, fromabout 84 mol % to about 94 mol %, from about 84 mol % to about 95 mol %,from about 84 mol % to about 92 mol %, or from about 84 mol % to about90 mol %), and H″ is from about 0 mol % (i.e., trace amounts) to about10 mol % (e.g., from about 0.001 mol % to about 10 mol %, from about0.001 mol % to about 9 mol %, from about 0.001 mol % to about 8 mol %,from about 0.001 mol % to about 7 mol %, from about 0.001 mol % to about6 mol %, from about 0.001 mol % to about 5 mol %, from about 0.001 mol %to about 4 mol %, from about 0.001 mol % to about 3 mol %, or from about0.001 mol % to about 2 mol %).

In certain embodiments of the associative polymers of formula (AP₃₋₁₁)(i.e., AP₃, AP₄, AP₅, AP₆, AP₇, AP₈, AP₉, AP₁₀, or AP₁₁), E″ is fromabout 0.005 mol % to about 1 mol % (e.g., from about 0.01 mol % to about1 mol %, from about 0.1 mol % to about 1 mol %, from about 0.25 mol % toabout 1 mol %, from about 0.3 mol % to about 1 mol %, from about 0.4 mol% to about 1 mol %, from about 0.5 mol % to about 1.0 mol %, from about0.01 mol % to about 0.5 mol %, or from about 0.01 mol % to about 0.25mol %), F″ is from about 4 mol % to about 10 mol % (e.g., from about 4mol % to about 9 mol %, from about 4 mol % to about 8 mol %, from about4 mol % to about 7 mol %, from about 4 mol % to about 6 mol %, fromabout 4 mol % to about 5 mol %, from about 5 mol % to about 10 mol %,from about 6 mol % to about 10 mol %, from about 7 mol % to about 10 mol%, from about 8 mol % to about 10 mol %, from about 9 mol % to about 10mol %, or from about 6 mol % to about 8 mol %), G″ is from about 84 mol% to about 90 mol % (e.g., from about 85 mol % to about 90 mol %, fromabout 86 mol % to about 90 mol %, from about 87 mol % to about 90 mol %,from about 88 mol % to about 90 mol %, from about 89 mol % to about 90mol %, from about 84 mol % to about 89 mol %, from about 84 mol % toabout 88 mol %, from about 84 mol % to about 87 mol %, from about 84 mol% to about 86 mol %, from about 84 mol % to about 85 mol %, or fromabout 86 mol % to about 88 mol %), and H″ is from about 0 mol % (i.e.,trace amounts) to about 6 mol % (e.g., from about 0.001 mol % to about 5mol %, from about 0.001 mol % to about 4 mol %, from about 0.001 mol %to about 3 mol %, or from about 0.001 mol % to about 2 mol %, from about0.001 mol % to about 1 mol %, from about 0.01 mol % to about 1 mol %,from about 0.1 mol % to about 1 mol %, from about 0.25 mol % to about 1mol %, from about 0.3 mol % to about 1 mol %, from about 0.4 mol % toabout 1 mol %, from about 0.5 mol % to about 1.0 mol %, from about 0.01mol % to about 0.5 mol %, or from about 0.01 mol % to about 0.25 mol %).

The processes provided herein comprise networking one or moreassociative polymer(s). As used herein, “networking” refers to chemicalcoordination of one polymer chain to an adjacent polymer chain topromote a different physical property. The networking technique cancomprise any suitable chemical coordination. Generally, the networkingof one or more associative polymer(s) does not comprise covalentlylinking adjacent polymer chains. For example, the chemical coordinationcan occur through ionic bonding, hydrogen bonding, hydrophobicinteractions, dipolar interactions, Van der Waals forces, or acombination thereof.

In an embodiment, at least a portion of the networking occurs betweenthe associative monomer units of different polymer chains (i.e.,intermolecular interactions). Without wishing to be bound by anyparticular theory, it is believed that associative monomer unitsinteract momentarily through weak chemical interactions (i.e., ionicbonding, hydrogen bonding, hydrophobic interactions, dipolarinteractions, Van der Waals forces, or a combination thereof), resultingin networking adjacent associative polymer(s) temporarily. As usedherein, “networking adjacent associative polymer(s) temporarily” refersto an interaction, which can be controlled by the level of dilution, thepresence of a surfactant, or a combination thereof. Thus, the networkingof associative polymer(s) is reversible, thereby allowing for powders,gels, or low viscosity liquid media to be prepared and/or subsequentlydispersed in a solvent.

In another embodiment, at least a portion of the networking occursbetween the associative monomer units and one or more surfactant(s).Without wishing to be bound by any particular theory, it is believedthat associative monomer units can interact momentarily through weakchemical interactions (i.e., ionic bonding, hydrogen bonding,hydrophobic interactions, dipolar interactions, Van der Waals forces, ora combination thereof) with the one or more surfactant(s), resulting innetworking the associative polymer(s) and surfactant(s) temporarily. Asused herein, “networking adjacent associative polymer(s) andsurfactant(s) temporarily” refers to an interaction, which can becontrolled by the level of dilution, the amount of a surfactant, or acombination thereof. Thus, the networking of associative polymer(s) andsurfactant(s) is reversible, and allows for powder, gels, or lowviscosity liquid media to be prepared and/or subsequently dispersed in asolvent.

In some embodiments, at least a portion of the networking occurs throughmicellar copolymerization. As used herein, “micellar copolymerization”refers to concurrent formation of micelles comprising associativemonomers and/or surfactant(s), and associative polymer(s) comprisingassociative monomer units. Without wishing to be bound by any particulartheory, it is believed that associative monomer units of adjacentpolymers can become incorporated into micelles formed from associativemonomers and/or surfactant(s), thereby networking the adjacentassociative polymer(s) polymers temporarily.

As used herein, “temporary networking” refers to an associativeinteraction (e.g., within the solution of associative polymer(s), thewet gel, and the powder) which can be controlled by the level ofdilution, the presence of a surfactant, or a combination thereof.Contrary to more permanent cross-linking practice known in the art,e.g., cross-linking via covalent bonds, temporary networking can bemomentary. As used herein, “temporary” can refer to any length of timeextending from the initial formation of the solution of associativepolymers to dispersion of the powder in solution. For example, temporarynetworking provides sufficient structure of the wet gel to allow formachine processing and conversion into a powder. In addition, temporarynetworking helps to produce a powder that is stable yet maintainsreasonable levels of water solubility. Upon dilution in water, theassociative interactions (i.e., the temporary networking) decrease, andthe powder becomes dispersed in the water or other solvent.

In certain embodiments, the process comprises networking one or moreassociative polymer(s) and one or more surfactant(s) wherein the one ormore associative monomer unit(s) and the one or more surfactant(s) arestructurally similar. As used herein, “structurally similar” means thatthe associative monomer unit(s) and the surfactant(s) have the same orsimilar chemical functional groups. In some embodiments, the associativemonomer unit(s) and the surfactant(s) each comprise at least onehydroxyl substituent. In some embodiments, the associative monomerunit(s) and the surfactant(s) each comprise at least one aminesubstituent. In some embodiments, the associative monomer unit(s) andthe surfactant(s) each comprise a polyether ether chain. In someembodiments, the associative monomer unit(s) and the surfactant(s) eachcomprise a polyether chain, wherein the length of the polyether chainsare separated by six carbon units or less (i.e., 6, 5, 4, 3, 2, 1, or0). For example, if an associative monomer unit has a polyether chainlength of 16 carbon units, then a structurally similar surfactant willhave a polyether chain length from 10-22 carbon units (i.e., 10, 11, 12,13, 14, 15, 16, 17, 18, 19, 20, 21, or 22). In certain embodiments, thepolyether chains comprise the same number of carbon units. In someembodiments, the associative monomer unit(s) and the surfactant(s) eachcomprise an alkyl chain. In some embodiments, the associative monomerunit(s) and the surfactant(s) each comprise alkyl chains, wherein thelength of the alkyl chains are separated by six carbon units or less(i.e., 6, 5, 4, 3, 2, 1, or 0). For example, if an associative monomerunit has an alkyl chain length of 16 carbon units, then a structurallysimilar surfactant will have an alkyl chain length from 10-22 carbonunits (i.e., 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, or 22). Incertain embodiments, the alkyl chains each comprise the same number ofcarbons. In certain embodiments, the associative monomer unit(s) and thesurfactant(s) comprise the same structural subunit.

In some embodiments, the process for making the powder further comprisesone or more surfactant(s). The surfactant can be any suitable surfactantselected from an anionic surfactant, a cationic surfactant, a nonionicsurfactant, and a combination thereof. In some embodiments, the one ormore surfactant(s) may exist as a dimer. For example, the surfactant canhave one polar head group and two non-polar tails, or two polar headgroups and one non-polar tail, or two polar head groups and twonon-polar tails. Without wishing to be bound to any particular theory,it is believed that the surfactant helps to provide structure to the wetgel and increases solubility of the resulting powder upon dilution inwater or other solvent.

In an embodiment, the surfactant is a cationic surfactant. In certainembodiments, the cationic surfactant is an ammonium salt of Formula IX:

wherein each R₁₁ is independently H or C₁-C₁₀ alkyl (e.g., (CH₂)_(e)CH₃)wherein e is an integer from 0 to 9 (i.e., 0, 1, 2, 3, 4, 5, 6, 7, 8, or9), A is any anion, and d is an integer from 6 to 34 (e.g., from 6 to30, from 6 to 24, from 6 to 20, from 6 to 16, from 6 to 12, from 5 to25, from 10 to 20, from 15 to 25, from 10 to 24, or from 10 to 30). Insome embodiments, “C₁-C₁₀ alkyl” refers to a branched C₁-C₁₀ alkylgroup. In some embodiments, the ammonium salt of Formula IX is a mixtureof two or more such ammonium salts, such that the average (rounded tothe nearest integer) value of d is an integer from 6 to 34 (e.g., from 6to 30, from 6 to 24, from 6 to 20, from 6 to 16, from 6 to 12, from 5 to25, from 10 to 20, from 15 to 25, from 10 to 24, or from 10 to 30). Incertain embodiments, the cationic surfactant ishexadecyltrimethylammonium p-toluenesulfonate orhexadecyltrimethylammonium chloride.

The ammonium salt can have any suitable anion counter ion (i.e., “A”).In some embodiments, the anion counter ion (“A”) comprises an elementselected from a halogen (i.e., fluoride, chloride, bromide, or iodide),sulfur, carbon, nitrogen, phosphorous, and a combination thereof. Anexemplary list of anions comprises fluoride, chloride, bromide, iodide,sulfide, sulfite, sulfate, bisulfate, bisulfite, thiosulfate, carbonate,bicarbonate, nitrate, nitrite, phosphate, hydrogen phosphate, dihydrogenphosphate, phosphite, hydrogen phosphite, dihydrogen phosphite,hexafluorophosphate, carboxylate, acetate, mesylate, tosylate, ortriflate. In certain embodiments, A is selected from fluoride, chloride,bromide, mesylate, tosylate, or a combination thereof.

In some embodiments, the surfactant is an anionic surfactant. In certainembodiments, the anionic surfactant is a sulfate salt of Formula X:

wherein B is any cation, and f is an integer from 7 to 35 (e.g., from 7to 29, from 7 to 23, from 7 to 19, from 7 to 15, from 7 to 11, from 11to 19, from 11 to 23, or from 11 to 29). In some embodiments, thesulfate salt of Formula X is a mixture of two or more such sulfatesalts, such that the average (rounded to the nearest integer) value offis an integer from 7 to 35 (e.g., from 7 to 29, from 7 to 23, from 7 to19, from 7 to 15, from 7 to 11, from 11 to 19, from 11 to 23, or from 11to 29). In certain embodiments, the anionic surfactant is sodiumdodecylsulfate (i.e., f is 11).

The sulfate salt can have any suitable cation counter ion (i.e., “B”).For example, the cation counter ion (“B”) can be a proton, ammonium, aquaternary amine, a cation of an alkali metal, a cation of an alkalineearth metal, a cation of a transition metal, a cation of a rare-earthmetal, a main group element cation, or a combination thereof. In someembodiments, the cation counter ion is hydrogen or a cation of lithium,sodium, potassium, magnesium, calcium, manganese, iron, zinc, or acombination thereof. In certain embodiments, B is selected fromhydrogen, lithium, sodium, potassium, or a combination thereof.

In some embodiments, the surfactant is a nonionic surfactant. Thenonionic surfactant can be any suitable nonionic surfactant. In someembodiments, the nonionic surfactant comprises repeating units ofethylene oxide, propylene oxide, or ethylene oxide and propylene oxide.In certain embodiments, the surfactant comprises block or randomcopolymers of ethylene oxide (“EO”), propylene oxide (“PO”), or acombination thereof.

In certain embodiments, the nonionic surfactant is of Formula XI:HO(C₂H₄O)_(a)(C₃H₆O)_(b)(C₂H₄O)_(c)H   XIwherein a, b, and c are independently integers ranging from about 2 toabout 200 (e.g., from about 2 to about 175, from about 2 to about 150,from about 2 to about 125, from about 2 to about 100, from about 50 toabout 200, from about 50 to about 150, or from about 50 to about 100),and a, b, and c are the same or different. In some embodiments, thenonionic surfactant of Formula X is a mixture of two or more suchsurfactants, such that a, b, and c refer to an average (rounded to thenearest integer) chain length of the designated subunits (i.e., averagechain length of EO and PO) wherein a, b, and c are independentlyintegers from about 2 to about 200 (e.g., from about 2 to about 175,from about 2 to about 150, from about 2 to about 125, from about 2 toabout 100, from about 50 to about 200, from about 50 to about 150, orfrom about 50 to about 100). In certain embodiments, the nonionicsurfactant is PLURONIC® F-127 surfactant, i.e.,HO(C₂H₄O)₁₀₁(C₃H₆O)₅₆(C₂H₄O)₁₀₁H, marketed by BASF Corporation (FlorhamPark, N.J.).

In some embodiments, the nonionic surfactant is of Formula XII:

wherein g is an integer ranging from about 6 to about 50 (e.g., fromabout 6 to about 42, from about 6 to about 36, from about 6 to about 30,from about 6 to about 24, from about 6 to about 18, from about 6 toabout 12, from about 8 to about 30, from about 12 to about 50, fromabout 12 to about 36, or from about 12 to about 24), each R₁₂ and R₁₃are independently H or C₁-C₄ alkyl (e.g., methyl, ethyl, n-propyl,iso-propyl, n-butyl, sec-butyl, or tert-butyl), and h and i areindependently integers ranging from 0 to about 100 (e.g., from about 0to about 90, from about 0 to about 80, from about 0 to about 70, fromabout 0 to about 60, from about 0 to about 50, from about 10 to about100, or from about 10 to about 50). In some embodiments, the surfactantof Formula XII is a mixture of two or more such surfactants, such thatg, h, and i refer to an average (rounded to the nearest integer) chainlength of the designated subunits (i.e., average carbon chain length oraverage EO (or substituted EO) chain length), wherein g is an integerfrom about 6 to about 50 (e.g., from about 6 to about 42, from about 6to about 36, from about 6 to about 30, from about 6 to about 24, fromabout 6 to about 18, from about 6 to about 12, from about 8 to about 30,from about 12 to about 50, from about 12 to about 36, or from about 12to about 24), and h and i are independently integers ranging from 0 toabout 100 (e.g., from about 0 to about 90, from about 0 to about 80,from about 0 to about 70, from about 0 to about 60, from about 0 toabout 50, from about 10 to about 100, or from about 10 to about 50).

In certain embodiments, the nonionic surfactant is of Formula XII:

wherein g is an integer ranging from about 6 to about 50 (e.g., fromabout 6 to about 42, from about 6 to about 36, from about 6 to about 30,from about 6 to about 24, from about 6 to about 18, from about 6 toabout 12, from about 12 to about 50, from about 12 to about 36, or fromabout 12 to about 24), R₁₂ and R₁₃ are H, and h and i are independentlyintegers ranging from 0 to about 100 (e.g., from about 0 to about 90,from about 0 to about 80, from about 0 to about 70, from about 0 toabout 60, from about 0 to about 50, from about 10 to about 100, or fromabout 10 to about 50). In certain embodiments, the surfactant is BRIJ®S20, i.e., a polyethylene glycol octadecyl ether of the formulaC₁₈H₃₇(OC₂H₄)_(h′)OH, wherein h′ is an integer ranging from about 2 toabout 200, marketed by Croda International PLC (East Yorkshire, UnitedKingdom).

In certain embodiments, the nonionic surfactant is of Formula XII:

wherein g is an integer ranging from about 6 to about 50 (e.g., fromabout 6 to about 42, from about 6 to about 36, from about 6 to about 30,from about 6 to about 24, from about 6 to about 18, from about 6 toabout 12, from about 12 to about 50, from about 12 to about 36, or fromabout 12 to about 24), i is 0, R₁₂ is H, and h is an integer rangingfrom about 2 to about 30 (e.g., from 2 to 30, from 4 to 30, from 6 to30, from 8 to 30, from 10 to 30, from 12 to 30, from 16 to 30, from 18to 30, from 20 to 30, from 22 to 30, or from 24 to 30). In certainembodiments, the surfactant is a Lutensol® fatty alcohol ethoxylatecommercially available from BASF Corporation (Florham Park, N.J.). Morepreferably, the surfactant is polyethoxy (25) cetyl and/or stearylalcohol, marketed under the product name (25 EO) C16-C18 fatty alcohol(“LutensolAT® 25”), commercially available from BASF Corporation(Florham Park, N.J.).

In certain embodiments, the nonionic surfactant is of Formula XII:

wherein g is an integer ranging from about 8 to about 30 (e.g., from 10to 30, from 12 to 30, from 16 to 30, from 18 to 30, from 20 to 30, from22 to 30, or from 24 to 30), each R₁₂ and R₁₃ are independently H orC₁-C₄ alkyl (e.g., methyl, ethyl, n-propyl, iso-propyl, n-butyl,sec-butyl, or tert-butyl), and h and i are independently integersranging from 0 to about 50 (e.g., from about 0 to about 40, from about 0to about 30, from about 0 to about 20, from about 10 to about 50, fromabout 10 to about 40, from about 10 to about 30, or from about 10 toabout 20). In certain embodiments, the surfactant is a Plurafac®surfactant, commercially available from BASF Corporation (Florham Park,N.J.).

In certain embodiments, the nonionic surfactant is of Formula XIII:

wherein w, x, y, and z are integers from about 0 to about 50 (e.g., fromabout 0 to about 40, from about 0 to about 30, from about 0 to about 20,from about 0 to about 16, from about 0 to about 12, or from about 0 toabout 8), and w, x, y, and z are the same or different. In someembodiments, the nonionic surfactant of Formula XIII is a mixture of twoor more such surfactants, such that w, x, y, and z refer to an average(rounded to the nearest integer) chain length of the designated subunits(i.e., average chain length of EO) wherein w, x, y, and z are integersfrom about 0 to about 50 (e.g., from about 0 to about 40, from about 0to about 30, from about 0 to about 20, from about 0 to about 16, fromabout 0 to about 12, or from about 0 to about 8). In certainembodiments, the nonionic surfactant is TWEEN® 20 surfactant, i.e.,w+x+y+z=20, marketed by Croda International PLC (East Yorkshire, UnitedKingdom).

When the one or more surfactant(s) is present in the powder, the one ormore surfactant(s) can be present in the powder at any suitableconcentration. The powder can comprise a sum total of about 20 wt. % orless of the surfactant(s), for example, about 15 wt. % or less, about 10wt. % or less, about 9 wt. % or less, about 8 wt. % or less, about 7 wt.% or less, about 6 wt. % or less, or about 5 wt. % or less.Alternatively, or in addition to, the powder can comprise a sum total ofabout 0.001 wt. % or more of the surfactant(s), for example, about 0.01wt. %, about 0.1 wt. %, about 0.25 wt. % or more, about 0.5 wt. % ormore, about 1 wt. % or more, about 2 wt. % or more, about 3 wt. % ormore, or about 4 wt. % or more. Thus, the powder can comprise the one ormore surfactant(s) in a concentration bounded by any two of theaforementioned endpoints. The powder can comprise a sum total of fromabout 0.001 wt. % to about 5 wt. %, from about 0.01 wt. % to about 5 wt.%, from about 0.1 wt. % to about 5 wt. % surfactant, for example, fromabout 0.25 wt. % to about 5 wt. %, from about 0.5 wt. % to about 5 wt.%, from about 1 wt. % to about 5 wt. %, from about 2 wt. % to about 5wt. %, from about 3 wt. % to about 5 wt. %, from about 4 wt. % to about5 wt. %, from about 4 wt. % to about 10 wt. %, from about 4 wt. % toabout 9 wt. %, from about 4 wt. % to about 8 wt. %, from about 4 wt. %to about 7 wt. %, from about 4 wt. % to about 6 wt. %, from about 0.001wt. % to about 10 wt. %, from about 0.01 wt. % to about 10 wt. %, fromabout 0.1 wt. % to about 10 wt. %, from about 0.001 wt. % to about 15wt. %, from about 0.01 wt. % to about 15 wt. %, from about 0.1 wt. % toabout 15 wt. %, from about 0.001 wt. % to about 20 wt. %, from about0.01 wt. % to about 20 wt. %, from about 0.1 wt. % to about 20 wt. %, orfrom about 0.001 wt. % to about 1 wt. %.

In an embodiment, the one or more surfactant(s) are added before theformation of the powder (e.g., to the polymer solution, before or afterpolymerization, or to the wet gel). When the surfactant(s) are addedbefore the formation of the powder, the surfactant(s) are incorporatedinto the wet gel, and thereby the powder. Generally, the surfactant(s)improve the processability of the wet gel into a powder. Typically thesurfactant(s) further improve the solubility or dispersibility of theresulting powder in aqueous media or other solvent.

In some embodiments, the one or more surfactant(s) is added to thepowder after being processed from the wet gel. In some embodiments, theone or more surfactant(s) are not necessary for the wet gel to beprocessed. In particular, the chemical interactions of the associativemonomer units may be strong enough to network the associative polymer(s)in the absence of surfactant(s). While the surfactant is not alwaysnecessary for the formation of the powder, the resulting powder (absentof one or more surfactant(s)) is generally less soluble in an aqueousmedium. For example, the one or more surfactant(s) tend to facilitatere-wetting of the associative polymer(s) and speed up the process offorming a solution in water. Thus, a surfactant can be added afterformation of the powder in order to improve solubility anddispersibility of the resulting powder in an aqueous medium or othersolvent.

The polymerization to form the associative polymer(s) can be carried outaccording to any suitable polymerization known in the art. For example,the associative polymer(s) can be made by emulsion polymerization,dispersion polymerization, solution polymerization, gel polymerization,or a combination thereof. The polymerization to form the associativepolymer(s) can occur through any suitable mechanism. For example, thepolymerization can occur through cationic polymerization, anionicpolymerization, free-radical polymerization, coordinationpolymerization, or combinations thereof. Typically, polymerizationoccurs through free radical polymerization.

In some embodiments, the polymerization to form the associativepolymer(s) comprises one or more polymerization component(s). In certainembodiments, the one or more polymerization component(s) are not removedfrom the reaction mixture such that one or more of the polymerizationcomponent(s) remains in the polymer solution, the polymer wet gel,and/or the powder. In other embodiments, the one or more polymerizationcomponent(s) are removed such that the one or more polymerizationcomponent(s) are not present in the polymer solution, the polymer wetgel, and/or the powder. In some embodiments, the one or morepolymerization component(s) are transformed such that one or moretransformed polymerization components are present in the polymersolution, the polymer wet gel, and/or the powder. An exemplary list ofpolymerization components is an initiator, a chain transfer agent, achelant, a redox agent, a buffer, and a combination thereof.

In some embodiments, the polymerization comprises one or moreinitiator(s). The initiator can be any suitable initiator. In someembodiments, the initiator is a free radical initiator. In certainembodiments, the initiator is selected from the group of azobiscompounds. An exemplary list of initiators is 2,2′-azobis(2,4-dimethylvaleronitrile), 2,2′-azobis(4-methoxy-2,4-dimethyl valeronitrile),1,1′-azobis(cyclohexane-1-carbonitrile),2,2′-azobis(2-methylbutyronitrile),2,2′-azobis(2-methylpropionamidine)dihydrochloride,2,2′-azobis[2-(2-imidazolin-2-yl)propane]dihydrochloride,2,2′-azobis[N-(2-carboxyethyl)-2-methylpropionamidine]hydrate(anhydride), and 2,2′-azobis[2-(2-imidazolin-2-yl)propane].

In some embodiments, the polymerization comprises one or more chaintransfer agent(s). The chain transfer agent can be any suitable chaintransfer agent. An exemplary list of chain transfer agents is carbontetrachloride, carbon tetrabromide, bromotrichloromethane,pentaphenylethane, sodium formate, sodium hypophosphite, thiophenol,4,4′-thiobisbenzenethiol, 4-methylbenzenethiol, and aliphatic thiolssuch as isooctyl 3-mercaptopropionate, tert-nonyl mercaptan, andN-acetyl-L-cysteine, N-2-mercaptoethyl)acetamide, glutathione,N-(2-mercaptopropionyl)glycine, and 2-mercaptoethanol.

In some embodiments, the polymerization comprises one or morechelant(s). The chelant can be any suitable chelant. In certainembodiments, the chelant is a polydentate organic compound. An exemplarylist of chelating agents is diethylenetriaminepentaacetic acid (“DTPA”),ethylenediaminetetraacetic acid (“EDTA”), nitrilotriacetic acid (“NTA”),diethylenetriaminepentaacetic acid, N,N-bis(carboxymethyl)-L-glutamicacid, trisodium N-(hydroxyethyl)-ethylenediaminetriacetate, adipic acid,and salts thereof.

In some embodiments, the polymerization comprises one or more redoxagent(s). The redox agent can be any suitable redox agent. In someembodiments, the redox agent aids in terminating the polymerization. Incertain embodiments, the redox reagent is an organic peroxide, aninorganic peroxide, or a combination thereof. An exemplary list of redoxagents is sodium bisulfate; a thiosulfate, ferrous ammonium sulfate;ascorbic acid, an amine, a hypophosphite, sodium bromate, a chlorate, apermanganate, ammonium persulfate, potassium persulfate, sodiumpersulfate, t-butyl hydrogen peroxide, hydrogen peroxide, ozone, andsalts thereof. In some embodiments, the redox agent is added as a redoxpair such that one agent participates in reduction and one agentparticipates in oxidation. In certain embodiments, the redox agent isthe initiator.

In some embodiments, the polymerization comprises a buffer system. Thebuffer system can be any suitable organic and/or inorganic buffersystem. In certain embodiments, the buffer system comprises an organicand/or inorganic acid and/or base capable of controlling the pH lowerthan about 6 (e.g., from about 0 to about 6, from about 1 to about 6,from about 2 to about 6, from about 3 to about 6, from about 4 to about6, from about 5 to about 6, from about 0 to about 1, from about 0 toabout 2, from about 0 to about 3, from about 0 to about 4, or from about0 to about 5). An exemplary list of buffers is adipic acid, pimelicacid, glutaric acid, citric acid, acetic acid, an inorganic acid (e.g.,phosphoric acid), an amine, and salts thereof.

The solution of one or more associative polymer(s) and optionally one ormore surfactant(s) can be converted to a wet gel by any suitabletechnique. In some embodiments, the solution of one or more associativepolymer(s) and optionally one or more surfactant(s) spontaneouslybecomes a wet gel. For example, the solution-based monomers canpolymerize in the presence of the one or more surfactant(s) andpolymerization results in a transition from solution-based monomers tosolution-based polymers which spontaneously begin to solidify to formthe polymer wet gel. In some embodiments, the solution of one or moreassociative polymer(s) and optionally one or more surfactant(s) may needto be dried prior to formation of a wet gel. For example, the solutionof one or more associative polymer(s) and optionally one or moresurfactant(s) can be converted to a wet gel through drying (e.g.,placing in an oven and/or ambient temperature evaporation), cooling,change in pressure, or a combination thereof. As used herein, “wet gel”refers to any material produced when a solution of one or moreassociative polymer(s) and optionally one or more surfactant(s)transitions from a fluid-like to solid-like state. In certainembodiments, the wet gel maintains a taffy-like consistency and is notsticky.

The wet gel comprises the resulting associatively networked polymer,optionally one or more surfactant(s), and a solvent. Generally, the wetgel contains about 20 wt. % to about 80 wt. % of the associativelynetworked polymer. In an embodiment, the polymer wet gel comprises fromabout 25 wt. % to about 50 wt. % polymer. In certain embodiments, thepolymer wet gel comprises from about 30 wt. % to about 40 wt. % polymer.

The wet gel can be processed to a powder by any suitable process. Insome embodiments, the wet gel is processed to a powder by cutting thewet gel to form granules, drying the granules, and converting the driedgranules to form a powder. In some embodiments, the wet gel is processedto a powder by drying the wet gel, cutting the dried wet gel intogranules, and converting the granules to a powder. In some embodiments,the wet gel is process to a powder by drying the wet gel, cutting thedried wet gel to granules, drying the granules, and converting the driedgranules to form a powder. The wet gel can be cut by any suitablemethod. In certain embodiments, the wet gel is machine processed (forexample, using a Retsch Mill Cutter) to form wet gel granules. Incertain embodiments, the wet gel is cut with the aid of a lubricant. Thelubricant can be any suitable lubricant (e.g., a petroleum oil basedlubricant). The wet gel granules can be converted to a powder by anysuitable method. In some embodiments, “converting the granules to form apowder” refers to the process of, for example, optionally drying thegranules further, grinding the granules, or drying and grinding thegranules to produce a powder, though the converting may include otherprocessing steps. For example, converting the granules to a powder canfurther comprise sifting.

The powder can have any suitable moisture content. Generally, themoisture content is from about 0 wt. % to about 30 wt. % (e.g., fromabout 0.01 wt. % to about 30 wt. %, from about 0.1 wt. % to about 30 wt.%, or from about 1 wt. % to about 30 wt. %). In certain embodiments ofthe powder, the moisture content is from about 0 wt. % to about 25 wt. %(e.g., from about 0.01 wt. % to about 25 wt. %, from about 0.1 wt. % toabout 25 wt. %, or from about 1 wt. % to about 25 wt. %). In certainembodiments of the powder, the moisture content is from about 0 wt. % toabout 20 wt. % (e.g., from about 0.01 wt. % to about 20 wt. %, fromabout 0.1 wt. % to about 20 wt. %, from about 0.1 wt. % to about 10 wt.%, or from about 1 wt. % to about 20 wt. %). In certain embodiments, themoisture content is about 10 wt. %.

The powder can have any suitable mean particle size (i.e., mean particlediameter). The mean particle size can be determined by any suitablemethod known in the art. Generally, the mean particle size is determinedby a Horiba Laser Scattering Particle Size Distribution Analyzer LA-950.The powder can have a mean particle size of about 1 micron or more, forexample, about 10 microns or more, about 20 microns or more, about 50microns or more, about 100 microns or more, about 200 microns or more,or about 500 microns or more. Alternatively, or in addition, the powdercan have a mean particle size of about 10,000 microns or less, forexample, about 8,000 microns or less, about 6,000 microns or less, about4,000 microns or less, or about 2,000 microns or less. Thus, the powdercan have a mean particle size bounded by any two of the aforementionedendpoints. The powder can have a mean particle size of from about 1micron to about 10,000 microns, for example, from about 1 micron toabout 8,000 microns, from about 1 micron to about 6,000 microns, fromabout 1 micron to about 4,000 microns, from about 1 micron to about2,000 microns, from about 10 microns to about 2,000 microns, from about20 microns to about 2,000 microns, from about 50 microns to about 2,000microns, from about 100 microns to about 2,000 microns, from about 200microns to about 2,000 microns, or from about 500 microns to about 2,000microns.

The powder can have any suitable particle shape. In some embodiments,the powder particles are non-spherical. Without wishing to be bound toany particular theory, it is believed that non-spherical particles aregenerally formed when the powder has been manufactured by a gel-,spray-, or drum-based process (e.g., via cutting and drying). In someembodiments, the powder particles are spherical. Without wishing to bebound to any particular theory, it is believed that spherical particlesare generally formed when the powder has been manufactured by abead-based process.

In some embodiments, the powder, at a median particle size of at least300 microns, is soluble as up to a 20 wt. % solution in water withstirring by a cage stirrer at 400 rpm within one hour at roomtemperature. In some embodiments, the powder, at a median particle sizeof at least 300 microns, is soluble as up to a 10 wt. % solution inwater with stirring by a cage stirrer at 400 rpm within one hour at roomtemperature. In certain embodiments, the powder, at a median particlesize of at least 300 microns, is soluble as up to a 5 wt. % solution inwater with stirring by a cage stirrer at 400 rpm within one hour at roomtemperature. In certain embodiments, the powder, at a median particlesize of at least 300 microns, is soluble as up to a 1 wt. % solution inwater with stirring by a cage stirrer at 400 rpm within one hour at roomtemperature. In some embodiments, generally, when the powder does notcomprise one or more surfactant(s), the powder, at a median particlesize of at least 300 microns, does not completely dissolve, or issparingly soluble in water (i.e., did not completely dissolve as a 1 wt.% solution in water within one hour at room temperature). Withoutwishing to be bound by any particular theory, it is believed that thechemical interactions (e.g., networking) diminish as the concentrationsof associative polymer(s) and optional surfactant(s) are reduced belowtheir critical concentration, thereby releasing the active polymerstrength aid (i.e., associative polymer) and further improvingsolubility. As used herein, “critical concentration” refers to theconcentration at which the associative polymer(s) and surfactant(s)transition from being solution-based to maintaining an organized networkstructure.

The resulting powder can have any suitable intrinsic viscosity. Forexample, the powder can have an intrinsic viscosity of from about 0.05dL/g to about 7 dL/g (e.g., from about 0.05 dL/g to about 6 dL/g., fromabout 0.05 dL/g to about 5 dL/g, from about 0.05 dL/g to about 4 dL/g,from about 0.05 dL/g to about 3 dL/g, from about 0.05 dL/g to about 2dL/g, from about 0.05 dL/g to about 1 dL/g, from about 0.05 dL/g toabout 0.5 dL/g, from about 0.1 dL/g to about 7 dL/g, from about 0.1 dL/gto about 6 dL/g, or from about 0.5 dL/g to about 5 dL/g). In someembodiments, the powder has an intrinsic viscosity from about 0.1 dL/gto about 6. In certain embodiments, the powder has an intrinsicviscosity of from about 0.5 dL/g to about 5 dL/g.

Intrinsic viscosity (“IV”) is defined by a series of reduced specificviscosity (“RSV”) measurements extrapolated to the limit of infinitedilution, i.e., when the concentration of powder is equal to zero. TheRSV is measured at a given powder concentration and temperature andcalculated as follows:

${R\; S\; V} = {\frac{\left( {\frac{\eta}{\eta_{0}} - 1} \right)}{c} = \frac{\left( {\frac{t}{t_{0}} - 1} \right)}{c}}$wherein η is viscosity of the powder solution, η₀ is viscosity of thesolvent at the same temperature, an t is elution time of powdersolution, t₀ is elution time of solvent, and c is concentration (g/dL)of the powder in solution. Thus, intrinsic viscosity is defined by dL/g.Variables t and to are measured using powder solution and solvent thatis in 1.0 N sodium nitrate solution with a Cannon Ubbelohde semimicrodilution viscometer (size 75) at 30±0.02° C.

The resulting powder can have any suitable Huggins constant. Forexample, the resulting powder can have a Huggins constant from about 0.1to about 20 (e.g., from about 0.1 to about 15, from about 0.1 to about10, from about 0.3 to about 10, from about 0.1 to about 5, from about0.5 to about 20, from about 0.5 to about 10, from about 1 to about 20,from about 1 to about 10, or from about 1 to about 5). In someembodiments, the powder can have a Huggins constant of from about 0.3 toabout 10 as determined by varying concentrations of the powder, whereinthe concentrations have been chosen such that they produce a value of

$\left( \frac{t}{t_{0}} \right)$between about 1.2 and 2.2, in a 1.0 N sodium nitrate solution. In someembodiments, the powder can have a Huggins constant of from about 0.3 toabout 5 as determined by varying concentrations of the powder, whereinthe concentrations have been chosen such that they produce a value of

$\left( \frac{t}{t_{0}} \right)$between about 1.2 and 2.2, in a 1.0 N sodium nitrate solution. Incertain embodiments, the powder has a Huggins constant of from about 0.6to about 3 as determined by varying concentrations of the powder,wherein the concentrations have been chosen such that they produce avalue of

$\left( \frac{t}{t_{0}} \right)$between about 1.2 and 2.2, in a 1.0 N sodium nitrate solution. TheHuggins constant is calculated as follows:

${{Huggins}\mspace{14mu}{constant}} = \frac{{slope}\mspace{14mu}{of}\mspace{14mu}\left( {R\; S\; V\text{∼}c} \right)}{{IV}^{2}}$

A powder is also provided herein. The powder comprises one or moreassociatively networked polymer(s) comprising one or more associativemonomer unit(s) and one or more monomer units selected from at least oneof a cationic monomer unit, an anionic monomer unit, a nonionic monomerunit, a zwitterionic monomer unit, or a combination thereof, andoptionally one or more surfactant(s), wherein the associative polymer(s)have a weight average molecular weight of from about 10 kDa to about2,000 kDa. In some embodiments, the powder comprises one or more lowmolecular weight associative polymer(s) that are reversibly associatedin a polymer network, wherein the association is controllable via degreeof dilution in aqueous media, or amount of surfactant present.

In some embodiments, the powder comprises a nonionic surfactant and anassociative polymer comprising an associative monomer unit derived froma monomer of Formula II, a monomer unit derived from a monomer ofFormula I, and an additional cationic monomer unit. In some embodiments,the powder comprises a nonionic surfactant and an associative polymercomprising an associative monomer unit derived from a monomer of FormulaII, a monomer unit derived from a monomer of Formula I, and anadditional monomer unit derived from DMAEA.MCQ. In some embodiments, thepowder comprises a nonionic surfactant and an associative polymercomprising an associative monomer unit derived from a monomer of FormulaII, an additional monomer unit derived from acrylamide, and anadditional monomer unit derived from DMAEA.MCQ. In certain embodiments,the powder comprises a nonionic surfactant and an associative polymercomprising an associative monomer unit derived from VISIOMER® monomerC18PEG1105MA, an additional monomer unit derived from acrylamide, and anadditional monomer unit derived from DMAEA.MCQ. In certain embodiments,the powder comprises a nonionic surfactant of Formula XII, and anassociative polymer comprising an associative monomer unit derived fromVISIOMER® monomer C18PEG1105MA, an additional monomer unit derived fromacrylamide, and an additional monomer unit derived from DMAEA.MCQ. Incertain embodiments, the powder comprises PLURONIC® F-127 surfactantand/or LutensolAT® 25 surfactant, and an associative polymer comprisingan associative monomer unit derived from VISIOMER® monomer C18PEG1105MA,an additional monomer unit derived from acrylamide, and an additionalmonomer unit derived from DMAEA.MCQ.

In some embodiments, the powder comprises a nonionic surfactant and anassociative polymer comprising an associative monomer unit derived froma monomer of Formula II, a monomer unit derived from a monomer ofFormula I, and an additional anionic monomer unit. In some embodiments,the powder comprises a nonionic surfactant and an associative polymercomprising an associative monomer unit derived from a monomer of FormulaII, a monomer unit derived from a monomer of Formula I, and anadditional monomer unit derived from sodium acrylate. In someembodiments, the powder comprises a nonionic surfactant and anassociative polymer comprising an associative monomer unit derived froma monomer of Formula II, an additional monomer unit derived fromacrylamide, and an additional monomer unit derived from sodium acrylate.In certain embodiments, the powder comprises a nonionic surfactant andan associative polymer comprising an associative monomer unit derivedfrom VISIOMER® monomer C18PEG1105MA, an additional monomer unit derivedfrom acrylamide, and an additional monomer unit derived from sodiumacrylate. In certain embodiments, the powder comprises a nonionicsurfactant of Formula XII, and an associative polymer comprising anassociative monomer unit derived from VISIOMER® monomer C18PEG1105MA, anadditional monomer unit derived from acrylamide, and an additionalmonomer unit derived from sodium acrylate. In certain embodiments, thepowder comprises PLURONIC® F-127 surfactant and/or LutensolAT® 25surfactant, and an associative polymer comprising an associative monomerunit derived from VISIOMER® monomer C18PEG1105MA, an additional monomerunit derived from acrylamide, and an additional monomer unit derivedfrom sodium acrylate.

In some embodiments, the powder comprises a cationic surfactant and anassociative polymer comprising an associative monomer unit derived froma monomer of Formula VI, a monomer unit derived from a monomer ofFormula I, and an additional cationic monomer unit. In some embodiments,the powder comprises a cationic surfactant and an associative polymercomprising an associative monomer unit derived from a monomer of FormulaVI, a monomer unit derived from a monomer of Formula I, and anadditional monomer unit derived from DMAEA.MCQ. In some embodiments, thepowder comprises a cationic surfactant and an associative polymercomprising an associative monomer unit derived from a monomer of FormulaVI, an additional monomer unit derived from acrylamide, and anadditional monomer unit derived from DMAEA.MCQ. In certain embodiments,the powder comprises a cationic surfactant and an associative polymercomprising an associative monomer unit derived from MAPTAC-C12derivative of Formula VII, an additional monomer unit derived fromacrylamide, and an additional monomer unit derived from DMAEA.MCQ. Incertain embodiments, the powder comprises a cationic surfactant ofFormula IX, and an associative polymer comprising an associative monomerunit derived from MAPTAC-C12 derivative of Formula VII, an additionalmonomer unit derived from acrylamide, and an additional monomer unitderived from DMAEA.MCQ. In certain embodiments, the powder comprisescetyltrimethylammonium chloride and/or hexadecyltrimethylammoniump-toluenesulfonate, and an associative polymer comprising an associativemonomer unit derived from MAPTAC-C12 derivative of Formula VII, anadditional monomer unit derived from acrylamide, and an additionalmonomer unit derived from DMAEA.MCQ.

In some embodiments, the powder comprises a cationic surfactant and anassociative polymer comprising an associative monomer unit derived froma monomer of Formula VI, a monomer unit derived from a monomer ofFormula I, and an additional anionic monomer unit. In some embodiments,the powder comprises a cationic surfactant and an associative polymercomprising an associative monomer unit derived from a monomer of FormulaVI, a monomer unit derived from a monomer of Formula I, and anadditional monomer unit derived from sodium acrylate. In someembodiments, the powder comprises a cationic surfactant and anassociative polymer comprising an associative monomer unit derived froma monomer of Formula VI, an additional monomer unit derived fromacrylamide, and an additional monomer unit derived from sodium acrylate.In certain embodiments, the powder comprises a cationic surfactant andan associative polymer comprising an associative monomer unit derivedfrom MAPTAC-C12 derivative of Formula VII, an additional monomer unitderived from acrylamide, and an additional monomer unit derived fromsodium acrylate. In certain embodiments, the powder comprises a cationicsurfactant of Formula IX, and an associative polymer comprising anassociative monomer unit derived from MAPTAC-C12 derivative of FormulaVII, an additional monomer unit derived from acrylamide, and anadditional monomer unit derived from sodium acrylate. In certainembodiments, the powder comprises cetyltrimethylammonium chloride and/orhexadecyltrimethylammonium p-toluenesulfonate, and an associativepolymer comprising an associative monomer unit derived from MAPTAC-C12derivative of Formula VII, an additional monomer unit derived fromacrylamide, and an additional monomer unit derived from sodium acrylate.

In some embodiments, the powder comprises an anionic surfactant and anassociative polymer comprising an associative monomer unit derived froma monomer of Formula VIII, a monomer unit derived from a monomer ofFormula I, and an additional cationic monomer unit. In some embodiments,the powder comprises an anionic surfactant and an associative polymercomprising an associative monomer unit derived from a monomer of FormulaVIII, a monomer unit derived from a monomer of Formula I, and anadditional monomer unit derived from DMAEA.MCQ. In some embodiments, thepowder comprises an anionic surfactant and an associative polymercomprising an associative monomer unit derived from a monomer of FormulaVIII, an additional monomer unit derived from acrylamide, and anadditional monomer unit derived from DMAEA.MCQ. In certain embodiments,the powder comprises an anionic surfactant of formula X, and anassociative polymer comprising an associative monomer unit derived froma monomer of Formula VIII, an additional monomer unit derived fromacrylamide, and an additional monomer unit derived from DMAEA.MCQ. Incertain embodiments, the powder comprises sodium dodecyl sulfate, and anassociative polymer comprising an associative monomer unit derived froma monomer of Formula VIII, an additional monomer unit derived fromacrylamide, and an additional monomer unit derived from DMAEA.MCQ.

In some embodiments, the powder comprises an anionic surfactant and anassociative polymer comprising an associative monomer unit derived froma monomer of Formula VIII, a monomer unit derived from a monomer ofFormula I, and an additional anionic monomer unit. In some embodiments,the powder comprises an anionic surfactant and an associative polymercomprising an associative monomer unit derived from a monomer of FormulaVIII, a monomer unit derived from a monomer of Formula I, and anadditional monomer unit derived from sodium acrylate. In someembodiments, the powder comprises an anionic surfactant and anassociative polymer comprising an associative monomer unit derived froma monomer of Formula VIII, an additional monomer unit derived fromacrylamide, and an additional monomer unit derived from sodium acrylate.In certain embodiments, the powder comprises an anionic surfactant offormula X, and an associative polymer comprising an associative monomerunit derived from a monomer of Formula VIII, an additional monomer unitderived from acrylamide, and an additional monomer unit derived fromsodium acrylate. In certain embodiments, the powder comprises sodiumdodecyl sulfate, and an associative polymer comprising an associativemonomer unit derived from a monomer of Formula VIII, an additionalmonomer unit derived from acrylamide, and an additional monomer unitderived from sodium acrylate.

The individual components of the powder, for example, the one or moreassociative polymer(s) and one or more optional surfactant(s), are asdefined by the parameters set forth herein.

The individual structures of the one or more associative polymer(s), forexample, the one or more associative monomer unit(s) and one or moremonomer unit(s) selected from at least one of a cationic monomer unit,an anionic monomer unit, a nonionic monomer unit, a zwitterionic monomerunit, or a combination thereof, are as defined by the parameters setforth herein.

The individual structures of the one or more surfactant(s) are asdefined by the parameters set forth herein.

The quantities of the individual components of the powder, for example,the amount of the one or more associative polymer(s) and optionally oneor more surfactant(s), are as defined by the parameters set forthherein.

The quantities of the individual monomer units of the associativepolymer(s), for example, the amount of the one or more associativemonomer unit(s) and one or more monomer unit(s) selected from at leastone of a cationic monomer unit, an anionic monomer unit, a nonionicmonomer unit, a zwitterionic monomer unit, or a combination thereof, areas defined by the parameters set forth herein.

In certain embodiments, the physical characteristics of the powder areas defined by the parameters set forth herein.

The invention is further illustrated by the following embodiments.

(1) A powder, comprising one or more associative polymer(s) comprisingone or more associative monomer unit(s) and one or more additionalmonomer unit(s) selected from at least one of a cationic monomer unit,an anionic monomer unit, a nonionic monomer unit, a zwitterionic monomerunit, or a combination thereof, and optionally one or moresurfactant(s), wherein the associative polymer(s) have a weight averagemolecular weight of from about 10 kDa to about 2,000 kDa.

(2) The powder of embodiment (1), wherein the one or more associativemonomer unit(s) is derived from an acrylate monomer, an acrylamidemonomer, or a combination thereof.

(3) The powder of embodiment (1) or (2), wherein the one or moreassociative polymer(s) comprises a nonionic associative monomer unit.

(4) The powder of embodiment (3), wherein the nonionic associativemonomer unit is derived from a monomer of Formula II:

wherein R₃ is H or C₁-C₁₀ alkyl, X is O or NH, m, n, and o areindependently integers from 0 to 100, wherein when (n+o)≤3, m is atleast 7, each Y₁ and Y₂ are independently H or C₁-C₄ alkyl, and R₄ is Hor a hydrophobic group.

(5) The powder of embodiment (4), wherein the nonionic associativemonomer unit is derived from a monomer of Formula III:

wherein R₅ is —CH₂(CH₂)_(p)CH₃, R₃ is H or C₁-C₁₀ alkyl, and p is aninteger from 3 to 100.

(6) The powder of embodiment (5), wherein the nonionic monomer unit isderived from laurylacrylate, cetylacrylate, stearylacrylate,behenylacrylate, or a combination thereof.

(7) The powder of embodiment (6), wherein the nonionic monomer unit isderived from laurylacrylate.

(8) The powder of embodiment (4), wherein the nonionic associativemonomer unit is derived from a monomer of Formula IV:

wherein R₃ is H or C₁-C₁₀ alkyl, q is an integer from 2 to 100, r is aninteger from 0 to 30, and each Y is independently H or CH₃.

(9) The powder of embodiment (8), wherein the nonionic monomer unit isderived from lauryl polyethoxy (25) methacrylate, cetyl polyethoxy (25)methacrylate, stearyl polyethoxy (25) methacrylate, behenyl polyethoxy(25) methacrylate, or a combination thereof.

(10) The powder of embodiment (9), wherein the nonionic monomer unit isderived from a mixture of cetyl polyethoxy (25) methacrylate and stearylpolyethoxy (25) methacrylate.

(11) The powder of embodiment (1) or (2), wherein the one or moreassociative polymer(s) comprises a cationic associative monomer unit.

(12) The powder of embodiment (11), wherein the cationic associativemonomer unit is derived from a monomer of Formula VI:

wherein R₆ and R₇ are each independently H or C₁-C₁₀ alkyl, X is O orNH, s is an integer from 0 to 20, Z is any anion, and R₈ is ahydrophobic group.

(13) The powder of embodiment (12), wherein the cationic associativemonomer unit is derived from a monomer of Formula VII:

wherein R₆ is H or C₁-C₁₀ alkyl, and u is an integer from 0 to 30.

(14) The powder of embodiment (13), wherein the cationic associativemonomer unit is derived from a monomer of Formula VII:

wherein R₆ is CH₃, and u is 10.

(15) The powder of embodiment (1) or (2), wherein the one or moreassociative polymer(s) comprises an anionic associative monomer unit.

(16) The powder of embodiment (15), wherein the anionic associativemonomer unit is derived from a monomer of Formula VIII:

wherein R₉ is H or C₁-C₁₀ alkyl, X is O or NH, M is any cation, and eachR₁₀ is independently H or an organic group.

(17) The powder of any one of embodiments (1)-(16), wherein theadditional monomer unit is derived from a monomer selected from amonomer of Formula I:

wherein R₁ is H or C₁-C₄ alkyl and each R₂ is independently H or anorganic group; 2-(dimethylamino)ethyl acrylate (“DMAEA”),2-(dimethylamino)ethyl methacrylate (“DMAEM”), 3-(dimethylamino)propylmethacrylamide (“DMAPMA”), 3-(dimethylamino)propyl acrylamide (“DMAPA”),3-methacrylamidopropyl-trimethyl-ammonium chloride (“MAPTAC”),3-acrylamidopropyl-trimethyl-ammonium chloride (“APTAC”), N-vinylpyrrolidone (“NVP”), N-vinyl acetamide, hydroxyethyl methacrylate,hydroxyethyl acrylate, diallyldimethylammonium chloride (“DADMAC”),diallylamine, vinylformamide,2-(acryloyloxy)-N,N,N-trimethylethanaminium chloride (“DMAEA.MCQ”),2-(methacryloyloxy)-N,N,N-trimethylethanaminium chloride (“DMAEM.MCQ”),N,N-dimethylaminoethyl acrylate benzyl chloride (“DMAEA.BCQ”),N,N-dimethylaminoethyl methacrylate benzyl chloride (“DMAEM.BCQ”),2-acrylamido-2-methylpropane sulfonic acid (“AMPS”),2-acrylamido-2-methylbutane sulfonic acid (“AMBS”),[2-methyl-2-[(1-oxo-2-propenyl)amino]propyl]-phosphonic acid,methacrylic acid, acrylic acid; salts thereof; and combinations thereof.

(18) The powder of embodiment (17), wherein the additional monomer unitis derived from a monomer of Formula I:

wherein R₁ is H or C₁-C₄ alkyl and each R₂ is independently H or anorganic group.

(19) The powder of embodiment (18), wherein the organic group is a C₁-C₆alkyl group.

(20) The powder of embodiment (18), wherein the additional monomer unitis derived from acrylamide.

(21) The powder of embodiment (19), wherein the additional monomer unitis derived from methacrylamide.

(22) The powder of embodiment (17), wherein the additional monomer unitis a cationic monomer unit derived from a monomer selected from2-(dimethylamino)ethyl acrylate (“DMAEA”), 2-(dimethylamino)ethylmethacrylate (“DMAEM”), 3-(dimethylamino)propyl methacrylamide(“DMAPMA”), 3-(dimethylamino)propyl acrylamide (“DMAPA”),3-methacrylamidopropyl-trimethyl-ammonium chloride (“MAPTAC”),3-acrylamidopropyl-trimethyl-ammonium chloride (“APTAC”),diallyldimethylammonium chloride (“DADMAC”), diallylamine,2-(acryloyloxy)-N,N,N-trimethylethanaminium chloride (“DMAEA.MCQ”),2-(methacryloyloxy)-N,N,N-trimethylethanaminium chloride (“DMAEM.MCQ”),N,N-dimethylaminoethyl acrylate benzyl chloride (“DMAEA.BCQ”),N,N-dimethylaminoethyl methacrylate benzyl chloride (“DMAEM.BCQ”), saltsthereof, and combinations thereof.

(23) The powder of embodiment (22), wherein the additional monomer unitis derived from 2-(acryloyloxy)-N,N,N-trimethylethanaminium chloride(“DMAEA.MCQ”).

(24) The powder of embodiment (22), wherein the additional monomer unitis derived from diallyldimethylammonium chloride (“DADMAC”).

(25) The powder of embodiment (17), wherein the additional monomer unitis an anionic monomer unit derived from a monomer selected from2-acrylamido-2-methylpropane sulfonic acid (“AMPS”),2-acrylamido-2-methylbutane sulfonic acid (“AMBS”),[2-methyl-2-[(1-oxo-2-propenyl)amino]propyl]-phosphonic acid,methacrylic acid, acrylic acid, salts thereof, and combinations thereof.

(26) The powder of embodiment (25), wherein the additional monomer unitis derived from acrylic acid.

(27) The powder of embodiment (25), wherein the additional monomer unitis derived from sodium acrylate.

(28) The powder of any one of embodiments (1-(27, wherein the powdercomprises one or more surfactant(s).

(29) The powder of embodiment (28), wherein the surfactant is an anionicsurfactant.

(30) The powder of embodiment (29), wherein the anionic surfactant is asulfate salt of Formula X:

wherein B is any cation, and f is an integer from 7 to 35.

(31) The powder of embodiment (30, wherein the anionic surfactant issodium dodecylsulfate.

(32) The powder of embodiment (28), wherein the surfactant is a cationicsurfactant.

(33) The powder of embodiment (32), wherein the cationic surfactant isan ammonium salt of Formula IX:

wherein each R₁₁ is independently H or C₁-C₁₀ alkyl, A is any anion, andd is an integer from 6 to 34.

(34) The powder of embodiment (33), wherein the cationic surfactant ishexadecyltrimethylammoniump-tolunesulfonate, hexadecyltrimethylammoniumchloride, or a combination thereof.

(35) The powder of embodiment (28), wherein the surfactant is nonionic.

(36) The powder of embodiment (35), wherein the nonionic surfactant is ablock or random polymer comprising ethylene oxide, propylene oxide, or acombination thereof.

(37) The powder of embodiment (36), wherein the polymer is of FormulaXI:HO(C₂H₄O)_(a)(C₃H₆O)_(b)(C₂H₄O)_(c)H,   XIwherein a, b, and c are integers ranging from about 2 to about 200 anda, b, and c are the same or different.

(38) The powder of embodiment (37), wherein the nonionic surfactant isHO(C₂H₄O)₁₀₁(C₃H₆O)₅₆(C₂H₄O)₁₀₁H.

(39) The powder of embodiment (35), wherein the nonionic surfactant isof Formula XII:

wherein g is an integer ranging from about 6 to about 50, each R₁₂ andR₁₃ are independently H or C₁-C₄ alkyl, and h and i are independentlyintegers ranging from 0 to about 100.

(40) The powder of embodiment (39), wherein the nonionic surfactant is apolyethylene glycol octadecyl ether of the formula C₁₈H₃₇(OC₂H₄)_(h′)OH,wherein h′ is an integer ranging from about 2 to about 200.

(41) The powder of embodiment (35), wherein the nonionic surfactant isof Formula XIII:

wherein w, x, y, and z are integers from about 0 to about 50, and w, x,y, and z are the same or different.

(42) The powder of embodiment (41), wherein the nonionic surfactant isTWEEN® 20 surfactant, i.e., w+x+y+z=20.

(43) The powder of embodiment (39), wherein the nonionic surfactant isof Formula XII:

wherein g is an integer ranging from about 6 to about 50, i is 0, R₁₂ isH, and h is an integer ranging from about 2 to about 30.

(44) The powder of embodiment (43), wherein the nonionic surfactant ispolyethoxy (25) lauryl alcohol, polyethoxy (25) cetyl alcohol,polyethoxy (25) stearyl alcohol, polyethoxy (25) behenyl alcohol, or acombination thereof.

(45) The powder of embodiment (44), wherein the nonionic surfactant is amixture of polyethoxy (25) cetyl alcohol and polyethoxy (25) stearylalcohol.

(46) The powder of any one of embodiments (1)-(45), wherein the one ormore associative polymer(s) comprises a sum total from about 0.005 mol %to about 10 mol % of the one or more associative monomer unit(s).

(47) The powder of embodiment (46), wherein the one or more associativepolymer(s) comprises a sum total from about 0.005 mol % to about 0.50mol % of the one or more associative monomer unit(s).

(48) The powder of embodiment (47), wherein the one or more associativepolymer(s) comprises a sum total from about 0.005 mol % to about 0.25mol % of the one or more associative monomer unit(s).

(49) The powder of any one of embodiments (1)-(48), wherein the one ormore associative polymer(s) comprises a sum total from about 90 mol % toabout 99.995 mol % of the one or more additional monomer unit(s).

(50) The powder of embodiment (49), wherein the one or more associativepolymer(s) comprises a sum total from about 99.5 mol % to about 99.995mol % of the one or more additional monomer unit(s).

(51) The powder of embodiment (50), wherein the one or more associativepolymer(s) comprises a sum total from about 99.75 mol % to about 99.995mol % of the one or more additional monomer unit(s).

(52) The powder of any one of embodiments (1)-(51), wherein the powder,at a median particle size of at least 300 microns, is completely solubleas up to a 1 wt. % solution in water with stirring by a cage stirrer at400 rpm within one hour at room temperature.

(53) The powder of embodiments (1)-(27), wherein the powder, at a medianparticle size of at least 300 microns, is sparingly soluble in water(i.e., did not completely dissolve as a 1 wt. % solution in water withinone hour at room temperature).

(54) The powder of any one of embodiments (1)-(53), wherein the one ormore associative polymer(s) have a weight average molecular weight offrom about 200 kDa to about 2,000 kDa.

(55) The powder of embodiment (54), wherein the one or more associativepolymer(s) have a weight average molecular weight of from about 500 kDato about 2,000 kDa.

(56) The powder of embodiment (55), wherein the one or more associativepolymer(s) have a weight average molecular weight of from about 800 kDato about 2,000 kDa.

(57) The powder of any one of embodiments (1)-(56), wherein the powderhas an intrinsic viscosity of from about 0.05 dL/g to about 7 dL/g.

(58) The powder of embodiment (57), wherein the powder has an intrinsicviscosity of from about 0.5 dL/g to about 5 dL/g.

(59) The powder of any one of embodiments (1)-(58), wherein the powderhas a Huggins constant of from about 0.3 to about 10.

(60) The powder of embodiment (59), wherein the powder has a Hugginsconstant of from about 0.3 to about 5.

(61) The powder of any one of embodiments (28)-(60), wherein the powdercomprises a sum total from about 0.001 wt. % to about 20 wt. % of theone or more surfactant(s).

(62) The powder of embodiment (28), wherein the powder comprisespolyethoxy (25) cetyl and/or stearyl alcohol, and an associative polymercomprising acrylamide, DMAEA.MCQ, and cetyl and/or stearyl polyethoxy(25) methacrylate.

(63) The powder of embodiment (28), wherein the powder comprisespolyethoxy (25) cetyl and/or stearyl alcohol, and an associative polymercomprising monomer units derived from acrylamide, sodium acrylate, andcetyl and/or stearyl polyethoxy (25) methacrylate.

(64) The powder of embodiment (28), wherein the powder compriseshexadecyltrimethylammonium p-tolunensulfonate and/orcetyltrimethylammonium chloride, and an associative polymer comprisingmonomer units derived from acrylamide, DMAEA.MCQ, and Formula VII:

wherein R₆ is CH₃, and u is 10.

(65) The powder of embodiment (28), wherein the powder compriseshexadecyltrimethylammonium p-tolunensulfonate and/orcetyltrimethylammonium chloride, and an associative polymer comprisingmonomer units derived from acrylamide, sodium acrylate, and Formula VII:

wherein R₆ is CH₃, and u is 10.

(66) An associative polymer of formula AP₁:

wherein E is one or more associative monomer unit(s), F is one or moreadditional monomer unit(s), G is one or more monomer unit(s) derivedfrom a monomer of Formula I, H is optionally present and is one or morepiperidine-2,6-dione unit(s), wherein the one or morepiperidine-2,6-dione(s) are formed upon cyclization of an acrylamidenitrogen of the monomer unit derived from a monomer of Formula I (“G”)on a carbonyl of the additional monomer unit (“F”), and wherein theassociative polymer has a weight average molecular weight of from about10 kDa to about 2,000 kDa.

(67) The associative polymer of embodiment (66), wherein H is notpresent, and the associative polymer is of the formula AP₂:

wherein E is one or more associative monomer unit(s), E′ is a molepercentage value of from about 0.005 to about 10, F is one or moreadditional monomer unit(s), F′ is a mole percentage value of from about0.005 to about 90, G is one or more monomer unit(s) derived from amonomer of Formula I, and G′ is a mole percentage value of from about 10to about 99.99.

(68) The associative polymer of embodiment (67), wherein E′ is fromabout 0.005 mol % to about 1 mol %, F′ is from about 4 mol % to about 16mol %, and G′ is from about 84 mol % to about 96 mol %.

(69) The associative polymer of embodiment (67) or 68), wherein E is anonionic associative monomer unit.

(70) The associative polymer of embodiment (69), wherein the nonionicassociative monomer unit is derived from a monomer of Formula II:

wherein R₃ is H or C₁-C₁₀ alkyl, X is O or NH, m, n, and o areindependently integers from 0 to 100, wherein when (n+o)≤3, m is atleast 7, each Y₁ and Y₂ are independently H or C₁-C₄ alkyl, and R₄ is Hor a hydrophobic group.

(71) The associative polymer of embodiment (70), wherein the nonionicassociative monomer unit is derived from a monomer of Formula III:

wherein R₅ is —CH₂(CH₂)_(p)CH₃, R₃ is H or C₁-C₁₀ alkyl, and p is aninteger from 3 to 100.

(72) The associative polymer of embodiment (71), wherein the nonionicmonomer unit is derived from laurylacrylate, cetylacrylate,stearylacrylate, behenylacrylate, or a combination thereof.

(73) The associative polymer of embodiment (72), wherein the nonionicmonomer unit is derived from laurylacrylate.

(74) The associative polymer of embodiment (70), wherein the nonionicassociative monomer unit is derived from a monomer of Formula IV:

wherein R₃ is H or C₁-C₁₀ alkyl, q is an integer from 2 to 100, r is aninteger from 0 to 30, and each Y is independently H or CH₃.

(75) The associative polymer of embodiment (74), wherein the nonionicmonomer unit is derived from lauryl polyethoxy (25) methacrylate, cetylpolyethoxy (25) methacrylate, stearyl polyethoxy (25) methacrylate,behenyl polyethoxy (25) methacrylate, or a combination thereof.

(76) The associative polymer of embodiment (75), wherein the nonionicmonomer unit is derived from a mixture of cetyl polyethoxy (25)methacrylate and stearyl polyethoxy (25) methacrylate.

(77) The associative polymer of embodiment (67) or (68), wherein E is acationic associative monomer unit.

(78) The associative polymer of embodiment (77), wherein the cationicassociative monomer unit is derived from a monomer of Formula VI:

wherein R₆ and R₇ are each independently H or C₁-C₁₀ alkyl, X is O orNH, s is an integer from 0 to 20, Z is any anion, and R₈ is ahydrophobic group.

(79) The associative polymer of embodiment (78), wherein the cationicassociative monomer unit is derived from a monomer of Formula VII:

wherein R₆ is H or C₁-C₁₀ alkyl, and u is an integer from 0 to 30.

(80) The associative polymer of embodiment (79), wherein the cationicassociative monomer unit is derived from a monomer of Formula VII:

wherein R₆ is CH₃, and u is 10.

(81) The associative polymer of embodiment (67) or (68), wherein E is ananionic associative monomer unit.

(82) The associative polymer of embodiment (81), wherein the anionicassociative monomer unit is derived from a monomer of Formula VIII:

wherein R₉ is H or C₁-C₁₀ alkyl, X is O or NH, M is any cation, and eachR₁₀ is independently H or a hydrophobic group.

(83) The associative polymer of any one of embodiments (67)-(82),wherein F is derived from a monomer selected from 2-(dimethylamino)ethylacrylate (“DMAEA”), 2-(dimethylamino)ethyl methacrylate (“DMAEM”),3-(dimethylamino)propyl methacrylamide (“DMAPMA”),3-(dimethylamino)propyl acrylamide (“DMAPA”),3-methacrylamidopropyl-trimethyl-ammonium chloride (“MAPTAC”),3-acrylamidopropyl-trimethyl-ammonium chloride (“APTAC”), N-vinylpyrrolidone (“NVP”), N-vinyl acetamide, hydroxyethyl methacrylate,hydroxyethyl acrylate, diallyldimethylammonium chloride (“DADMAC”),diallylamine, vinylformamide,2-(acryloyloxy)-N,N,N-trimethylethanaminium chloride (“DMAEA.MCQ”),2-(methacryloyloxy)-N,N,N-trimethylethanaminium chloride (“DMAEM.MCQ”),N,N-dimethylaminoethyl acrylate benzyl chloride (“DMAEA.BCQ”),N,N-dimethylaminoethyl methacrylate benzyl chloride (“DMAEM.BCQ”),2-acrylamido-2-methylpropane sulfonic acid (“AMPS”),2-acrylamido-2-methylbutane sulfonic acid (“AMBS”),[2-methyl-2-[(1-oxo-2-propenyl)amino]propyl]-phosphonic acid,methacrylic acid, acrylic acid, salts thereof, and combinations thereof.

(84) The associative polymer of embodiment (83), wherein F is derivedfrom a monomer selected from diallyldimethylammonium chloride(“DADMAC”), 2-(acryloyloxy)-N,N,N-trimethylethanaminium chloride(“DMAEA.MCQ”), acrylic acid, methacrylic acid, salts thereof, andcombinations thereof.

(85) The associative polymer of any one of embodiments (67)-(84),wherein G is derived from a monomer of Formula I:

wherein R₁ is H or C₁-C₄ alkyl and each R₂ is independently H or anorganic group.

(86) The associative polymer of embodiment (85), wherein the organicgroup is a C₁-C₆ alkyl group.

(87) The associative polymer of embodiment (86), wherein G is derivedfrom a monomer selected from acrylamide, methacrylamide, or acombination thereof.

(88) The associative polymer of embodiment (66), wherein H is present,and the associative polymer is of the formula AP₃:

wherein E is one or more associative monomer unit(s), E″ is a molepercentage value of from about 0.005 to about 10, F is one or moreadditional monomer unit(s), F″ is a mole percentage value of from about0.005 to about 90, G is one or more monomer unit(s) derived from amonomer of Formula I, G″ is a mole percentage value of from about 10 toabout 99.99, H is one or more piperidine-2,6-dione unit(s), and H″ is amole percentage value of from about 0 (i.e., trace amounts) to about 10.

(89) The associative polymer of embodiment (88), wherein H is of theformula

wherein R₁ is H or C₁-C₄ alkyl, and R₂ is H or an organic group.

(90) The associative polymer of embodiment (89), wherein the organicgroup is a C₁-C₆ alkyl group.

(91) The associative polymer of embodiment (89), wherein R₁ and R₂ arehydrogen.

(92) The associative polymer of any one of embodiments (88)-(91),wherein E″ is from about 0.005 mol % to about 1 mol %, F″ is from about4 mol % to about 10 mol %, G″ is from about 84 mol % to about 90 mol %,and H″ is from about 0 mol % (i.e., trace amounts) to about 10 mol %.

(93) The associative polymer of any one of embodiments (88)-(92),wherein E is a nonionic associative monomer unit.

(94) The associative polymer of embodiment (93), wherein the nonionicassociative monomer unit is derived from a monomer of Formula II:

wherein R₃ is H or C₁-C₁₀ alkyl, X is O or NH, m, n, and o areindependently integers from 0 to 100, wherein when (n+o)≤3, m is atleast 7, each Y₁ and Y₂ are independently H or C₁-C₄ alkyl, and R₄ is Hor a hydrophobic group.

(95) The associative polymer of embodiment (94), wherein the nonionicassociative monomer unit is derived from a monomer of Formula III:

wherein R₅ is —CH₂(CH₂)_(p)CH₃, R₃ is H or C₁-C₁₀ alkyl, and p is aninteger from 3 to 100.

(96) The associative polymer of embodiment (95), wherein the nonionicmonomer unit is derived from laurylacrylate, cetylacrylate,stearylacrylate, behenylacrylate, or a combination thereof.

(97) The associative polymer of embodiment (96), wherein the nonionicmonomer unit is derived from laurylacrylate.

(98) The associative polymer of embodiment (93), wherein the nonionicassociative monomer unit is derived from a monomer of Formula IV:

wherein R₃ is H or C₁-C₁₀ alkyl, q is an integer from 2 to 100, r is aninteger from 0 to 30, and each Y is independently H or CH₃.

(99) The associative polymer of embodiment (94), wherein the nonionicmonomer unit is derived from lauryl polyethoxy (25) methacrylate, cetylpolyethoxy (25) methacrylate, stearyl polyethoxy (25) methacrylate,behenyl polyethoxy (25) methacrylate, or a combination thereof.

(100) The associative polymer of embodiment (99), wherein the nonionicmonomer unit is derived from a mixture of cetyl polyethoxy (25)methacrylate and stearyl polyethoxy (25) methacrylate.

(101) The associative polymer of any one of embodiments (88)-(92),wherein E is a cationic associative monomer unit.

(102) The associative polymer of embodiment (101), wherein the cationicassociative monomer unit is derived from a monomer of Formula VI:

wherein R₆ and R₇ are each independently H or C₁-C₁₀ alkyl, X is O orNH, s is an integer from 0 to 20, Z is any anion, and R₈ is ahydrophobic group.

(103) The associative polymer of embodiment (102), wherein the cationicassociative monomer unit is derived from a monomer of Formula VII:

wherein R₆ is H or C₁-C₁₀ alkyl, and u is an integer from 0 to 30.

(104) The associative polymer of embodiment (103), wherein the cationicassociative monomer unit is derived from a monomer of Formula VII:

wherein R₆ is CH₃, and u is 10.

(105) The associative polymer of any one of embodiments (88)-(92),wherein E is an anionic associative monomer unit.

(106) The associative polymer of embodiment (105), wherein the anionicassociative monomer unit is derived from a monomer of Formula VIII:

wherein R₉ is H or C₁-C₁₀ alkyl, X is O or NH, M is any cation, and eachR₁₀ is independently H or a hydrophobic group.

(107) The associative polymer of any one of embodiments (88)-(106),wherein G is derived from a monomer of Formula I:

wherein R₁ is H or C₁-C₄ alkyl and each R₂ is independently H or anorganic group.

(108) The associative polymer of embodiment (107), wherein the organicgroup is a C₁-C₆ alkyl group.

(109) The associative polymer of embodiment (107), wherein G is derivedfrom acrylamide.

(110) The associative polymer of embodiment (108), wherein G is derivedfrom methacrylamide.

(111) The associative polymer of any one of embodiments (88)-(110),wherein F is derived from a monomer selected from 2-(dimethylamino)ethylacrylate (“DMAEA”), 2-(dimethylamino)ethyl methacrylate (“DMAEM”),3-(dimethylamino)propyl methacrylamide (“DMAPMA”),3-(dimethylamino)propyl acrylamide (“DMAPA”),3-methacrylamidopropyl-trimethyl-ammonium chloride (“MAPTAC”),3-acrylamidopropyl-trimethyl-ammonium chloride (“APTAC”), N-vinylpyrrolidone (“NVP”), N-vinyl acetamide, hydroxyethyl methacrylate,hydroxyethyl acrylate, diallyldimethylammonium chloride (“DADMAC”),diallylamine, vinylformamide,2-(acryloyloxy)-N,N,N-trimethylethanaminium chloride (“DMAEA.MCQ”),2-(methacryloyloxy)-N,N,N-trimethylethanaminium chloride (“DMAEM.MCQ”),N,N-dimethylaminoethyl acrylate benzyl chloride (“DMAEA.BCQ”),N,N-dimethylaminoethyl methacrylate benzyl chloride (“DMAEM.BCQ”),2-acrylamido-2-methylpropane sulfonic acid (“AMPS”),2-acrylamido-2-methylbutane sulfonic acid (“AMBS”),[2-methyl-2-[(1-oxo-2-propenyl)amino]propyl]-phosphonic acid,methacrylic acid, acrylic acid, salts thereof, and combinations thereof.

(112) The associative polymer of embodiment (111), wherein F is acationic monomer unit derived from a monomer selected from2-(dimethylamino)ethyl acrylate (“DMAEA”), 2-(dimethylamino)ethylmethacrylate (“DMAEM”), 3-(dimethylamino)propyl methacrylamide(“DMAPMA”), 3-(dimethylamino)propyl acrylamide (“DMAPA”),3-methacrylamidopropyl-trimethyl-ammonium chloride (“MAPTAC”),3-acrylamidopropyl-trimethyl-ammonium chloride (“APTAC”), N-vinylpyrrolidone (“NVP”), diallyldimethylammonium chloride (“DADMAC”),diallylamine, vinylformamide,2-(acryloyloxy)-N,N,N-trimethylethanaminium chloride (“DMAEA.MCQ”),2-(methacryloyloxy)-N,N,N-trimethylethanaminium chloride (“DMAEM.MCQ”),N,N-dimethylaminoethyl acrylate benzyl chloride (“DMAEA.BCQ”),N,N-dimethylaminoethyl methacrylate benzyl chloride (“DMAEM.BCQ”), saltsthereof, and combinations thereof.

(113) The associative polymer of embodiment (112), wherein F is derivedfrom 2-(acryloyloxy)-N,N,N-trimethylethanaminium chloride (“DMAEA.MCQ”).

(114) The associative polymer of embodiment (112), wherein theadditional monomer unit is derived from diallyldimethylammonium chloride(“DADMAC”).

(115) The associative polymer of embodiment (111), wherein F is ananionic monomer unit derived from a monomer selected from2-acrylamido-2-methylpropane sulfonic acid (“AMPS”),2-acrylamido-2-methylbutane sulfonic acid (“AMBS”),[2-methyl-2-[(1-oxo-2-propenyl)amino]propyl]-phosphonic acid,methacrylic acid, acrylic acid, salts thereof, and combinations thereof.

(116) The associative polymer of embodiment (115), wherein F is derivedfrom acrylic acid.

(117) The associative polymer of embodiment (115), wherein F is derivedfrom sodium acrylate.

(118) The associative polymer of any one of embodiments (66)-(117),wherein the associative polymer has a weight average molecular weight offrom about 200 kDa to about 2,000 kDa.

(119) The associative polymer of embodiment (118), wherein theassociative polymer has a weight average molecular weight of from about500 kDa to about 2,000 kDa.

(120) The associative polymer of embodiment (119), wherein theassociative polymer has a weight average molecular weight of from about800 kDa to about 2,000 kDa.

(121) The associative polymer of embodiment (88), wherein theassociative polymer is of the formula AP₄:

wherein each R₁ is independently H or C₁-C₄ alkyl, each R₂ isindependently H or an organic group, R₃ is H or C₁-C₁₀ alkyl, X is O orNH, m, n, and o are independently integers from 0 to 100, wherein when(n+o)≤3, m is at least 7, each Y₁ and Y₂ are independently H or C₁-C₄alkyl, and R₄ is H or a hydrophobic group.

(122) The associative polymer of embodiment (88), wherein theassociative polymer is of the formula AP₆:

wherein r is an integer from 0 to 30 and each Y is independently H orCH₃.

(123) The associative polymer of embodiment (88), wherein theassociative polymer is of the formula AP₇:

wherein each R₁ is independently H or C₁-C₄ alkyl, each R₂ isindependently H or an organic group, R₆ and R₇ are each independently Hor C₁-C₁₀ alkyl, X is O or NH, s is an integer from 0 to 20, Z is anyanion, and R₈ is a hydrophobic group.

(124) The associative polymer of embodiment (88), wherein theassociative polymer is of the formula AP₉:

wherein R₆ is H or C₁-C₁₀ alkyl, and u is an integer from 0 to 30.

(125) The associative polymer of embodiment (88), wherein theassociative polymer is of the formula AP₁₁:

wherein R₉ is H or C₁-C₁₀ alkyl, X is O or NH, M is any cation, and eachR₁₀ is independently H or a hydrophobic group.

(126) A process for making a powder, comprising forming a powder from awet gel, wherein the wet gel comprises one or more associativepolymer(s), and optionally one or more surfactant(s), wherein the one ormore associative polymer(s) have a weight average molecular weight offrom about 10 kDa to about 2,000 kDa.

(127) The process of embodiment (126), wherein the wet gel is machineprocessed to a powder.

(128) The process of embodiment (126) or (127), wherein the one or moreassociative polymer(s) comprises one or more associative monomer(s) unitderived from an acrylate monomer, acrylamide monomer, or a combinationthereof.

(129) The process of any one of embodiments (126)-(128), wherein the oneor more associative polymer(s) comprises a nonionic associative monomerunit.

(130) The process of embodiment (129), wherein the nonionic associativemonomer unit is derived from a monomer of Formula II:

wherein R₃ is H or C₁-C₁₀ alkyl, X is O or NH, m, n, and o areindependently integers from 0 to 100, wherein when (n+o)≤3, m is atleast 7, each Y₁ and Y₂ are independently H or C₁-C₄ alkyl, and R₄ is Hor a hydrophobic group.

(131) The process of embodiment (130), wherein the nonionic associativemonomer unit is derived from a monomer of Formula III:

wherein R₅ is —CH₂(CH₂)_(p)CH₃, R₃ is H or C₁-C₁₀ alkyl, and p is aninteger from 3 to 100.

(132) The process of embodiment (131), wherein the nonionic monomer unitis derived from laurylacrylate, cetylacrylate, stearylacrylate,behenylacrylate, or a combination thereof.

(133) The process of embodiment (132), wherein the nonionic monomer unitis derived from laurylacrylate.

(134) The process of embodiment (130), wherein the nonionic associativemonomer unit is derived from a monomer of Formula IV:

wherein R₃ is H or C₁-C₁₀ alkyl, q is an integer from 2 to 100, r is aninteger from 0 to 30, and each Y is independently H or CH₃.

(135) The process of embodiment (132), wherein the nonionic monomer unitis derived from lauryl polyethoxy (25) methacrylate, cetyl polyethoxy(25) methacrylate, stearyl polyethoxy (25) methacrylate, behenylpolyethoxy (25) methacrylate, or a combination thereof.

(136) The process of embodiment (135), wherein the nonionic monomer unitis derived from a mixture of cetyl polyethoxy (25) methacrylate andstearyl polyethoxy (25) methacrylate.

(137) The process of any one of embodiments (126)-(128), wherein the oneor more associative polymer(s) comprises a cationic associative monomerunit.

(138) The process of embodiment (137), wherein the cationic associativemonomer unit is derived from a monomer of Formula VI:

wherein R₆ and R₇ are each independently H or C₁-C₁₀ alkyl, X is O orNH, s is an integer from 0 to 20, Z is any anion, and R₈ is ahydrophobic group.

(139) The process of embodiment (138), wherein the cationic associativemonomer unit is derived from a monomer of Formula VII:

wherein R₆ is H or C₁-C₁₀ alkyl, and u is an integer from 0 to 30.

(140) The process of embodiment (139), wherein the cationic associativemonomer unit is derived from a monomer of Formula VII:

wherein R₆ is CH₃, and u is 10.

(141) The process of any one of embodiments (126)-(128), wherein the oneor more associative polymer(s) comprises an anionic associative monomerunit.

(142) The process of embodiment (141), wherein the anionic associativemonomer unit is derived from a monomer of Formula VIII:

wherein R₉ is H or C₁-C₁₀ alkyl, X is O or NH, M is any cation, and eachR₁₀ is independently H or a hydrophobic group.

(143) The process of any one of embodiments (126)-(142), wherein the oneor more associative polymer(s) comprise one or more additional monomerunit(s) selected from a cationic monomer unit, an anionic monomer unit,a nonionic monomer unit, and a combination thereof.

(144) The process of embodiment (143), wherein the additional monomerunit is derived from a monomer selected from a monomer of Formula I:

wherein R₁ is H or C₁-C₄ alkyl and each R₂ is independently H or anorganic group; 2-(dimethylamino)ethyl acrylate (“DMAEA”),2-(dimethylamino)ethyl methacrylate (“DMAEM”), 3-(dimethylamino)propylmethacrylamide (“DMAPMA”), 3-(dimethylamino)propyl acrylamide (“DMAPA”),3-methacrylamidopropyl-trimethyl-ammonium chloride (“MAPTAC”),3-acrylamidopropyl-trimethyl-ammonium chloride (“APTAC”), N-vinylpyrrolidone (“NVP”), N-vinyl acetamide, hydroxyethyl methacrylate,hydroxyethyl acrylate, diallyldimethylammonium chloride (“DADMAC”),diallylamine, vinylformamide,2-(acryloyloxy)-N,N,N-trimethylethanaminium chloride (“DMAEA.MCQ”),2-(methacryloyloxy)-N,N,N-trimethylethanaminium chloride (“DMAEM.MCQ”),N,N-dimethylaminoethyl acrylate benzyl chloride (“DMAEA.BCQ”),N,N-dimethylaminoethyl methacrylate benzyl chloride (“DMAEM.BCQ”),2-acrylamido-2-methylpropane sulfonic acid (“AMPS”),2-acrylamido-2-methylbutane sulfonic acid (“AMBS”),[2-methyl-2-[(1-oxo-2-propenyl)amino]propyl]-phosphonic acid,methacrylic acid, acrylic acid; salts thereof; and combinations thereof.

(145) The process of embodiment (143) or (144), wherein the additionalmonomer unit is derived from a monomer of Formula I:

wherein R₁ is H or C₁-C₄ alkyl and each R₂ is independently H or anorganic group.

(146) The process of embodiment (145), wherein the organic group is aC₁-C₆ alkyl group.

(147) The process of embodiment (145), wherein the additional monomerunit is derived from acrylamide.

(148) The process of embodiment (146), wherein the additional monomerunit is derived from methacrylamide.

(149) The process of embodiment (144), wherein the additional monomerunit is a cationic monomer unit derived from a monomer selected from2-(dimethylamino)ethyl acrylate (“DMAEA”), 2-(dimethylamino)ethylmethacrylate (“DMAEM”), 3-(dimethylamino)propyl methacrylamide(“DMAPMA”), 3-(dimethylamino)propyl acrylamide (“DMAPA”),3-methacrylamidopropyl-trimethyl-ammonium chloride (“MAPTAC”),3-acrylamidopropyl-trimethyl-ammonium chloride (“APTAC”),diallyldimethylammonium chloride (“DADMAC”), diallylamine,2-(acryloyloxy)-N,N,N-trimethylethanaminium chloride (“DMAEA.MCQ”),2-(methacryloyloxy)-N,N,N-trimethylethanaminium chloride (“DMAEM.MCQ”),N,N-dimethylaminoethyl acrylate benzyl chloride (“DMAEA.BCQ”),N,N-dimethylaminoethyl methacrylate benzyl chloride (“DMAEM.BCQ”), saltsthereof, and combinations thereof.

(150) The process of embodiment (149), wherein the additional monomerunit is derived from 2-(acryloyloxy)-N,N,N-trimethylethanaminiumchloride (“DMAEA.MCQ”).

(151) The process of embodiment (149), wherein the additional monomerunit is derived from diallyldimethylammonium chloride (“DADMAC”).

(152) The process of embodiment (144), wherein the additional monomerunit is an anionic monomer unit derived from a monomer selected from2-acrylamido-2-methylpropane sulfonic acid (“AMPS”),2-acrylamido-2-methylbutane sulfonic acid (“AMBS”),[2-methyl-2-[(1-oxo-2-propenyl)amino]propyl]-phosphonic acid,methacrylic acid, acrylic acid, salts thereof, and combinations thereof.

(153) The process of embodiment (152), wherein the additional monomerunit is derived from acrylic acid.

(154) The process of embodiment (152), wherein the additional monomerunit is derived from sodium acrylate.

(155) The process of any one of embodiments (126)-(154), wherein the wetgel comprises one or more surfactant(s).

(156) The process of embodiment (155), wherein the surfactant is ananionic surfactant.

(157) The process of embodiment (156), wherein the anionic surfactant isa sulfate salt of Formula X:

wherein B is any cation, and f is an integer from 7 to 35.

(158) The process of embodiment (157), wherein the anionic surfactant issodium dodecylsulfate.

(159) The process of embodiment (155), wherein the surfactant is acationic surfactant.

(160) The process of embodiment (159), wherein the cationic surfactantis an ammonium salt of Formula IX:

wherein each R₁₁ is independently H or C₁-C₁₀ alkyl, A is any anion, andd is an integer from 6 to 34.

(161) The process of embodiment (160), wherein the cationic surfactantis hexadecyltrimethylammoniump-tolunesulfonate,hexadecyltrimethylammonium chloride, or a combination thereof.

(162) The process of embodiment (155), wherein the surfactant isnonionic.

(163) The process of embodiment (162), wherein the nonionic surfactantis a block or random polymer comprising ethylene oxide, propylene oxide,or a combination thereof.

(164) The process of embodiment (163), wherein the polymer is of FormulaXI:HO(C₂H₄O)_(a)(C₃H₆O)_(b)(C₂H₄O)_(c)H,   XIwherein a, b, and c are integers ranging from about 2 to about 200 anda, b, and c are the same or different.

(165) The process of embodiment (164), wherein the nonionic surfactantis HO(C₂H₄O)₁₀₁(C₃H₆O)₅₆(C₂H₄O)₁₀₁H.

(166) The process of embodiment (165), wherein the nonionic surfactantis of Formula XII:

wherein g is an integer ranging from about 6 to about 50, each R₁₂ andR₁₃ are independently H or C₁-C₄ alkyl, and h and i are independentlyintegers ranging from 0 to about 100.

(167) The process of embodiment (166), wherein the nonionic surfactantis a polyethylene glycol octadecyl ether of the formulaC₁₈H₃₇(OC₂H₄)_(h′)OH, wherein h′ is an integer ranging from about 2 toabout 200.

(168) The process of embodiment (162), wherein the nonionic surfactantis of Formula XIII:

wherein w, x, y, and z are integers from about 0 to about 50, and w, x,y, and z are the same or different.

(169) The process of embodiment (168), wherein the nonionic surfactantis TWEEN® 20 surfactant, i.e., w+x+y+z=20.

(170) The process of embodiment (166), wherein the nonionic surfactantis of Formula XII:

wherein g is an integer ranging from about 6 to about 50, i is 0, R₁₂ isH, and h is an integer ranging from about 2 to about 30.

(171) The process of embodiment (170), wherein the nonionic surfactantis polyethoxy (25) lauryl alcohol, polyethoxy (25) cetyl alcohol,polyethoxy (25) stearyl alcohol, polyethoxy (25) behenyl alcohol, or acombination thereof.

(172) The process of embodiment (171), wherein the nonionic surfactantis a mixture of polyethoxy (25) cetyl alcohol and polyethoxy (25)stearyl alcohol.

(173) The process of any one of embodiments (155)-(172), wherein the oneor more associative polymer(s) are formed in the presence of asurfactant.

(174) The process of any one of embodiments (126)-(172), wherein the oneor more associative polymer(s) are formed in the absence of asurfactant.

(175) The process of embodiment (174), wherein one or more surfactant(s)are added to the powder.

(176) The process of any one of embodiments (126)-(175), wherein thepowder, at a median particle size of at least 300 microns, is completelysoluble as up to a 1 wt. % solution in water with stirring by a cagestirrer at 400 rpm within one hour at room temperature.

(177) The process of any one of embodiments (126)-(154), wherein thepowder, at a median particle size of at least 300 microns, is sparinglysoluble in water (i.e., did not completely dissolve as a 1 wt. %solution in water within one hour at room temperature).

(178) The process of any one of embodiments (126)-(177), wherein the oneor more associative polymer(s) have a weight average molecular weight offrom about 200 kDa to about 2,000 kDa.

(179) The process of embodiment (178), wherein the one or moreassociative polymer(s) have a weight average molecular weight of fromabout 500 kDa to about 2,000 kDa.

(180) The process of embodiment (179), wherein the one or moreassociative polymer(s) have a weight average molecular weight of fromabout 800 kDa to about 2,000 kDa.

(181) The process of any one of embodiments (126)-(180), wherein thepowder has an intrinsic viscosity of from about 0.05 dL/g to about 7dL/g.

(182) The process of embodiment (181), wherein the powder has anintrinsic viscosity of from about 0.5 dL/g to about 5 dL/g.

(183) The process of any one of embodiments (126)-(182), wherein thepowder has a Huggins constant of from about 0.3 to about 10.

(184) The process of embodiment (183), wherein the powder has a Hugginsconstant of from about 0.3 to about 5.

The following examples further illustrate the invention but, of course,should not be construed as in any way limiting its scope.

Example 1

This example, provided as a control, demonstrates the effect on theinability to be machine processed into a powder, exhibited by a lowmolecular weight polymer without networking via an associative monomerunit or a surfactant.

Polymer 1 (control) comprising 95/5 mol % acrylamide/DMAEA.MCQ wassynthesized in the following manner:

An 1,000 g aqueous solution at pH 2-5 containing 34 wt. % monomermixture of 95/5 mol % acrylamide/DMAEA.MCQ, azo initiator, chaintransfer agent, buffer agent, and chelant was chilled to approximately−5° C. and de-gassed with nitrogen. Polymerization was initiated with apair of redox agents and proceeded adiabatically until the conversion ofmonomer reached more than 99.99% to get the targeted molecular weight of1×10⁶ g/mol. The resulting polymer gel was too soft and sticky to beprocessed with the aid of 1 wt. % (relative to weight of polymer gel)petroleum oil based lubricant in a cutting mill (Restch Mill Cutter) at1500 rpm. The resulting polymer gel was manually divided into smallpieces on a tray and dried in an oven at 85° C. to remove the moistureand then ground to powder with an intrinsic viscosity of 3.20 dg/L andHuggins constant of 0.31 in 1.0 N NaNO₃ solution at 30° C. The weightaverage molecular weight was determined by hydrolysis (using 0.1 wt. %solution of NaOH at pH 12 with a cage stirrer at 400 rpm for one hour)of the resulting polymer, followed by size exclusion chromatography.

As is apparent from the results set forth in Table 1, low molecularweight Polymer 1, lacking temporary networking via an associativemonomer, was incapable of being machine processed to form a powder. Thiswas further evidenced by the procedure requiring manual division of thesoft and sticky polymer.

TABLE 1 Intrinsic Weight Average Viscosity Huggins Molecular Weight WetGel Polymer (dg/L) Constant (kDa) Processable 1 3.20 0.31 930 No 2 2.911.05 820 Yes 3 1.96 1.36 490 Yes

Example 2

This example demonstrates the effect on the ability to be machineprocessed into a powder, exhibited by a low molecular weight polymercomprising temporary networking via an associative monomer unit and asurfactant.

Polymer 2 comprising 94.94/5/0.06 mol %acrylamide/DMAEA.MCQ/C18PEG1105MA was synthesized in the followingmanner:

An 1,000 g aqueous solution at pH 2-5 containing 34 wt. % monomermixture of 94.94/5/0.06 mol % acrylamide/DMAEA.MCQ/C18PEG1105MA(VISIOMER® monomer; 55% active; Evonik Industries, Essen, Germany), 1wt. % of PLURONIC® F127 surfactant (BASF Corporation, Florham Park,N.J.), azo initiator, chain transfer agent, buffer agent, and chelantwas chilled to approximately −5° C. and de-gassed with nitrogen.Polymerization was initiated with a pair of redox agents and proceededadiabatically until the conversion of monomer reached more than 99.99%to get the targeted molecular weight of 1×10⁶ g/mol. The resulting wetgel, which maintained a taffy like consistency and was not sticky, wasprocessed with the aid of 1 wt. % (relative to weight of polymer gel)petroleum oil based lubricant in a cutting mill (Retsch Mill Cutter) at1500 rpm to form granules. The wet gel granules were dried in a meshtray in an oven at 85° C. to decrease the moisture content to about 10wt. % and then ground to powder having an intrinsic viscosity of 2.91dg/L and Huggins constant of 1.05 in 1 N NaNO₃ solution at 30° C. Theweight average molecular weight was determined by hydrolysis (using 0.1wt. % solution of NaOH at pH 12 with a cage stirrer at 400 rpm for onehour) of the resulting polymer, followed by size exclusionchromatography.

As is apparent from the results set forth in Table 1, low molecularweight Polymer 2, comprising temporary networking, was capable of beingmachine processed to form a powder. This was further evidenced by theprocedure allowing for use of a cutting mill to process the wet gel.

Example 3

This example demonstrates the effect on the ability to be processed intoa powder, exhibited by a low molecular weight polymer comprisingtemporary networking via an associative monomer unit and surfactant.

Polymer 3 comprising 94.84/5/0.12 mol %acrylamide/DMAEA.MCQ/C18PEG1105MA was synthesized in the followingmanner:

An 1,000 g aqueous solution at pH 2-5 containing 34 wt. % monomermixture of 94.8/5/0.12 mol % acrylamide/DMAEA.MCQ/C18PEG1105MA(VISIOMER® monomer; 55% active; Evonik Industries, Essen, Germany), 1wt. % of PLURONIC® F127 surfactant (BASF Corporation, Florham Park,N.J.), azo initiator, chain transfer agent, buffer agent, and chelantwas chilled to approximately −5° C. and de-gassed with nitrogen.Polymerization was initiated with a pair of redox agents and proceededadiabatically until the conversion of monomer reached more than 99.99%to get the targeted molecular weight of 0.5×10⁶ g/mol. The resulting wetgel, which maintained a taffy like consistency and was not sticky, wasprocessed with the aid of 1 wt. % (relative to weight of polymer gel)petroleum oil based lubricant in a cutting mill (Retsch Mill Cutter) at1500 rpm to form granules. The wet gel granules were dried in a meshtray in an oven at 85° C. to decrease the moisture content to about 10wt. % and then ground to powder having an intrinsic viscosity of 1.96dg/L and Huggins constant of 1.36 in 1 N NaNO₃ solution at 30° C. Theweight average molecular weight was determined by hydrolysis (using 0.1wt. % solution of NaOH at pH 12 with a cage stirrer at 400 rpm for onehour) of the resulting polymer, followed by size exclusionchromatography.

As is apparent from the results set forth in Table 1, low molecularweight Polymer 3, comprising temporary networking, was capable of beingmachine processed to form a powder. This was further evidenced by theprocedure allowing for use of a cutting mill to process the wet gel.

Example 4

This example demonstrates the effect on the ability to be machineprocessed into a powder, exhibited by a low molecular weight polymercomprising temporary networking via an associative monomer unit only(i.e., not further comprising a surfactant in the monomer phase).

Polymer 4 comprising 89.965/10/0.035 mol %acrylamide/DMAEA.MCQ/C18PEG1105MA was synthesized in the followingmanner:

An 1,000 g aqueous solution at pH 2-5 containing 37 wt. % monomermixture of 89.965/10/0.035 mol % acrylamide/DMAEA.MCQ/C18PEG1105MA(VISIOMER® monomer; 55% active; Evonik Industries, Essen, Germany), azoinitiator, chain transfer agent, buffer agent, and chelant was chilledto approximately −5° C. and de-gassed with nitrogen. Polymerization wasinitiated with a pair of redox agents and proceeded adiabatically untilthe conversion of monomer reached more than 99.99% to get the targetedmolecular weight of 1.0×10⁶ g/mol. The resulting wet gel, whichmaintained a taffy like consistency and was not sticky, was marginallyprocessed with the aid of 1 wt. % (relative to weight of polymer gel)petroleum oil based lubricant in a cutting mill (Retsch Mill Cutter) at1500 rpm to form granules. The wet gel granules were dried in a meshtray in an oven at 85° C. to decrease the moisture content to about 10wt. % and then ground to powder. The resulting powder had a medianparticle size of 568.9 microns (the mean particle size was 634.4), asdetermined using a Horiba Laser Scattering Particle Size DistributionAnalyzer LA-950 with the setting of refractive index of powder at1.5000. The powder did not completely dissolve as a 1 wt. % solution insynthetic tap water with stirring of cage stirrer at 400 rpm within onehour. The powder, as a 1 wt. % solution in synthetic tap water, had aviscosity of 744 cps, as measured on a Brookfield Model DV-E Viscometerwith Spindle 62 at 30 rpm. The weight average molecular weight wasdetermined by hydrolysis (using 0.1 wt. % solution of NaOH at pH 12 witha cage stirrer at 400 rpm for one hour) of the resulting polymer,followed by size exclusion chromatography.

As is apparent from the results set forth in Table 2, low molecularweight Polymer 4, not comprising a surfactant, was marginally capable ofbeing machine processed to form a powder. The resulting powder wassparingly soluble in water (i.e., did not completely dissolve as a 1 wt.% solution in local tap water with stirring of cage stirrer at 400 rpmwithin one hour).

TABLE 2 Weight Viscosity Average Surfactant of 1 wt. MW in powder WetGel % solution Polymer (kDa) (wt. %) Processable Solubility in water(cps) 4 840 0 Yes Poor 744 (marginal) 5 930 2.2 Yes Good 317

Example 5

This example demonstrates the effect on the ability to be machineprocessed into a powder, exhibited by a low molecular weight polymercomprising temporary networking via an associative monomer unit andsurfactant.

Polymer 5 comprising 89.965/10/0.035 mol %acrylamide/DMAEA.MCQ/C18PEG1105MA was synthesized in the followingmanner:

An 1,000 g aqueous solution at pH 2-5 containing 37 wt. % monomermixture of 89.965/10/0.035 mol % acrylamide/DMAEA.MCQ/C18PEG1105MA(VISIOMER® monomer; 55% active; Evonik Industries, Essen, Germany), 1wt. % LutensolAT® 25 surfactant, or ethoxylated (25 mol EO) C16-18 fattyalcohol (BASF Corporation, Florham Park, N.J.), azo initiator, chaintransfer agent, buffer agent, and chelant was chilled to approximately−5° C. and de-gassed with nitrogen. Polymerization was initiated with apair of redox agents and proceeded adiabatically until the conversion ofmonomer reached more than 99.99% to get the targeted molecular weight of1.0×10⁶ g/mol. The resulting wet gel, which maintained a taffy likeconsistency and was not sticky, was processed with the aid of 1 wt. %(relative to weight of polymer gel) petroleum oil based lubricant in acutting mill (Retsch Mill Cutter) at 1500 rpm to form granules. The wetgel granules were dried in a mesh tray in an oven at 85° C. to decreasethe moisture content to about 10 wt. % and then ground to powder. Theresulting powder had a median particle size of 559.7 microns (the meanparticle size was 609.3), as determined using a Horiba Laser ScatteringParticle Size Distribution Analyzer LA-950 with the setting ofrefractive index of powder at 1.5000. The powder completely dissolved asa 1 wt. % solution in synthetic tap water with stirring of cage stirrerat 400 rpm within one hour. The powder polymer, as a 1 wt. % solution insynthetic tap water, had a viscosity of 317 cps, as measured on aBrookfield Model DV-E Viscometer with Spindle 62 at 30 rpm. The weightaverage molecular weight was determined by hydrolysis (using 0.1 wt. %solution of NaOH at pH 12 with a cage stirrer at 400 rpm for one hour)of the resulting polymer, followed by size exclusion chromatography. Thestructure of Polymer 5 was further analyzed by ¹³C NMR spectroscopy(FIG. 1) to quantify the amount of piperidine-2,6-dione present in thepolymer. The ¹³C NMR sample was prepared in deuterated water and thecarbon spectrum was acquired using an Agilent Inova 500 Mhz spectrometerequipped with a Z-gradient and broadband 10 mm probe.

As is apparent from the results set forth in Table 2, low molecularweight Polymer 5, comprising a surfactant, was easily machine processedto form a powder. In addition, the resulting powder, comprising 2.2 wt.% surfactant, was completely soluble as a 1 wt. % solution in local tapwater with stirring of cage stirrer at 400 rpm within one hour.

In addition, the presence of the piperidine-2,6-dione monomer unit canbe verified by ¹³C NMR spectroscopy with a signature peak at 177 ppm inthe ¹³C NMR spectrum (FIG. 1). The relative amount of thepiperidine-2,6-dione monomer unit can be quantified by integration ofthe peak at 177 ppm, followed by a relative comparison to theintegration of other ¹³C NMR signals indicative of other monomer units.Integration analysis demonstrates that Polymer 5 comprises 7.8/90/2.1mol % DMAEA.MCQ-acrylamide-piperidine-2,6-dione. Note that theassociative monomer unit is present in such low concentrations thatsignature peaks of the associative monomer unit are not visible by ¹³CNMR spectroscopy.

Example 6

This example, provided as a control, demonstrates the effect on theinability to be machine processed into a powder, exhibited by a lowmolecular weight polymer without networking via an associative monomerunit or a surfactant.

Polymer 6 (control) comprising 50/50 mol % acrylamide/sodium acrylatewas synthesized in the following manner:

An 1,000 g aqueous solution at neutral pH containing 37 wt. % monomermixture of 50/50 mol % acrylamide/sodium acrylate, azo initiator, chaintransfer agent, and chelant was chilled to approximately −5° C. andde-gassed with nitrogen. Polymerization was initiated with a pair ofredox agents and proceeded adiabatically until the conversion of monomerreached more than 99.99% to get the targeted molecular weight of 1.0×10⁶g/mol. The resulting polymer wet gel was too soft and sticky to beprocessed with the aid of 1 wt. % (relative to weight of polymer gel)petroleum oil based lubricant in a cutting mill (Retsch Mill Cutter) at1500 rpm. The resulting wet gel was manually divided small pieces on atray and dried in an oven at 85° C. to remove the moisture and thenground to powder with an intrinsic viscosity of 5.80 dg/L and Hugginsconstant of 0.24 in 1 N NaNO₃ solution at 30° C. The weight averagemolecular weight was determined by size exclusion chromatography.

As is apparent from the results set forth in Table 3, low molecularweight Polymer 6, lacking temporary networking via an associativemonomer unit, was incapable of being machine processed to form a powder.This was further evidenced by the procedure requiring manual division ofthe soft and sticky polymer.

TABLE 3 Weight Avearge Intrinsic Huggins MW of Surrogate Wet Gel PolymerViscosity (dg/L) Constant (kDa) Processable 6 5.80 0.24 1,100 No 7 5.830.84 1,100 Yes 8 3.49 2.49 1,100 Yes 9 5.84 0.98 1,100 Yes

Example 7

This example demonstrates the effect on the ability to be machineprocessed into a powder, exhibited by a low molecular weight polymercomprising temporary networking via an associative monomer unit andsurfactant.

Polymer 7 comprising 49.9/50/0.1 mol % acrylamide/sodiumacrylate/MAPTAC-C12 derivative synthesized in the following manner:

An 1,000 g aqueous solution at neutral pH containing 37 wt. % monomermixture of 49.9/50/0.1 mol % acrylamide/sodium acrylate/MAPTAC-C12derivative, 0.5 wt. % of hexadecyltrimethylammonium p-toluenesulfonate(Sigma-Aldrich, St. Louis, Mo.), azo initiator, chain transfer agent,and chelant was chilled to approximately −5° C. and de-gassed withnitrogen. Polymerization was initiated with a pair of redox agents andproceeded adiabatically until the conversion of monomer reached morethan 99.99% to get the targeted molecular weight of 1.0×10⁶ g/mol. Theresulting wet gel, which maintained a taffy like consistency and was notsticky, was processed with the aid of 1 wt. % (relative to weight ofpolymer gel) petroleum oil based lubricant in a cutting mill (RetschMill Cutter) at 1500 rpm to form granules. The wet gel granules weredried in a mesh tray in an oven at 85° C. to decrease the moisturecontent to about 10 wt. % and then ground to powder. The resultingpowder had a median particle size of 357.1 microns (the mean particlesize was 420.1), as determined using a Horiba Laser Scattering ParticleSize Distribution Analyzer LA-950 with the setting of refractive indexof powder at 1.5000. The powder had an intrinsic viscosity of 5.83 dg/Land Huggins constant of 0.84 in 1.0 N NaNO₃ solution at 30° C. Thepowder completely dissolved as a 1 wt. % solution in synthetic tap waterwith stirring of cage stirrer at 400 rpm within one hour. The powder, asa 1 wt. % solution in synthetic tap water, had a viscosity of 1976 cps,as measured on a Brookfield Model DV-E Viscometer with Spindle 63 at 30rpm. The weight average molecular weight was determined by sizeexclusion chromatography using surrogate, Polymer 6.

As is apparent from the results set forth in Table 3, low molecularweight Polymer 7, comprising a surfactant, was easily machine processedto form a powder. In addition, Table 4 shows that the resulting powder,comprising 1.3 wt. % surfactant, was completely soluble as a 1 wt. %solution in local tap water with stirring of cage stirrer at 400 rpmwithin one hour.

Example 8

This example demonstrates the effect on the ability to be machineprocessed into a powder, exhibited by a low molecular weight polymercomprising temporary networking via an associative monomer unit and asurfactant.

Polymer 8 comprising 89.9/10/0.1 mol % acrylamide/sodiumacrylate/MAPTAC-C12 derivative synthesized in the following manner:

An 1,000 g aqueous solution at neutral pH containing 33 wt. % monomermixture of 89.9/10/0.1 mol % acrylamide/sodium acrylate/MAPTAC-C12derivative, 0.5 wt. % of hexadecyltrimethylammonium p-toluenesulfonate(Sigma-Aldrich, St. Louis, Mo.), azo initiator, chain transfer agent,and chelant was chilled to approximately −5° C. and de-gassed withnitrogen. Polymerization was initiated with a pair of redox agents andproceeded adiabatically until the conversion of monomer reached morethan 99.99% to get the targeted molecular weight of 1.0×10⁶ g/mol. Theresulting wet gel, which maintained a taffy like consistency and was notsticky, was processed with the aid of 1 wt. % (relative to weight ofpolymer gel) petroleum oil based lubricant in a cutting mill (RetschMill Cutter) at 1500 rpm to form granules. The wet gel granules weredried in a mesh tray in an oven at 85° C. to decrease the moisturecontent to about 10 wt. % and then ground to powder. The resultingpowder had a median particle size of 396.2 microns (the mean particlesize was 463.6), as determined using a Horiba Laser Scattering ParticleSize Distribution Analyzer LA-950 with the setting of refractive indexof powder at 1.5000. The powder had an intrinsic viscosity of 3.49 dg/Land Huggins constant of 2.49 in 1 N NaNO₃ solution at 30° C. The powdercompletely dissolved as a 1 wt. % solution in synthetic tap water withstirring of cage stirrer at 400 rpm within one hour. The powder, as a 1wt. % solution in tap water, had a viscosity of 2748 cps, as measured ona Brookfield Model DV-E Viscometer with Spindle 63 at 30 rpm. The weightaverage molecular weight was determined by size exclusion chromatographyusing a surrogate polymer formed with the same synthetic procedurecontaining 90/10 mol % acrylamide/sodium acrylate in the absence of theMAPTAC-C12 derivative.

As is apparent from the results set forth in Table 3, low molecularweight Polymer 8, comprising a surfactant, was easily machine processedto form a powder. In addition, Table 4 shows that the resulting powder,comprising 1.3 wt. % surfactant, was completely soluble as a 1 wt. %solution in local tap water with stirring of cage stirrer at 400 rpmwithin one hour.

TABLE 4 Weight Avearge Viscosity MW of Surfactant of 1 wt. % Surrogatein powder Wet Gel solution in Polymer (kDa) (wt. %) ProcessableSolubility water (cps) 7 1,100 1.3 Yes Good 1976 8 1,100 1.3 Yes Good2748 9 1,100 0 Yes Poor 1588

Example 9

This example demonstrates the effect on the ability to be machineprocessed into a powder, exhibited by a low molecular weight polymercomprising temporary networking via an associative monomer only (i.e.,not further comprising a surfactant in the monomer phase).

Polymer 9 comprising 49.9/50/0.1 mol % acrylamide/sodiumacrylate/MAPTAC-C12 derivative synthesized in the following manner:

An 1,000 g aqueous solution at neutral pH containing 37 wt. % monomermixture of 49.9/50/0.1 mol % acrylamide/sodium acrylate/MAPTAC-C12derivative, azo initiator, chain transfer agent, and chelant was chilledto approximately −5° C. and de-gassed with nitrogen. Polymerization wasinitiated with a pair of redox agents and proceeded adiabatically untilthe conversion of monomer reached more than 99.99% to get the targetedmolecular weight of 1.0×10⁶ g/mol. The resulting wet gel, whichmaintained a taffy like consistency and was not sticky, was processedwith the aid of 1 wt. % (relative to weight of polymer gel) petroleumoil based lubricant in a cutting mill (Retsch Mill Cutter) at 1500 rpmto form granules. The wet gel granules were dried in a mesh tray in anoven at 85° C. to remove (i.e., to achieve a moisture content of about10 wt. %) the moisture and then ground to powder. The resulting powderhad a median particle size of 385.4 microns (the mean particle size was446.4), as determined using a Horiba Laser Scattering Particle SizeDistribution Analyzer LA-950 with the setting of refractive index ofpowder at 1.5000. The powder had an intrinsic viscosity of 5.84 dg/L andHuggins constant of 0.98 in 1 N NaNO₃ solution at 30° C. The powderpolymer did not completely dissolve as a 1 wt. % solution in synthetictap water with stirring of cage stirrer at 400 rpm within one hour. Thepowder, as a 1 wt. % solution in synthetic tap water, had a viscosity of1588 cps, as measured on a Brookfield Model DV-E Viscometer with Spindle63 at 30 rpm. The weight average molecular weight was determined by sizeexclusion chromatography using surrogate, Polymer 6.

As is apparent from the results set forth in Table 4, low molecularweight Polymer 9, not comprising a surfactant, was capable of beingmachine processed to form a powder. The resulting powder was sparinglysoluble in water (i.e., did not completely dissolve as a 1 wt. %solution in local tap water with stirring of cage stirrer at 400 rpmwithin one hour).

Example 10

This example demonstrates the effect on paper dry strength exhibited bya sheet of paper treated with a powder comprising associativelynetworked polymer(s) via an associative monomer unit and a surfactant.

Polymer 2 (prepared according to Example 2) and Polymer 3 (preparedaccording to Example 3) were dissolved in water and dosed at variousconcentrations into cellulose fiber slurry. The treated fibers were thenadded to a handsheet mold and drained through a screen to form wet fiberpads. The pads were couched from the screen, pressed, and dried to yieldfinished paper sheets. The sheets were tested for tensile strength andcompressive strength and the results set forth in FIGS. 2 and 3,respectively. In addition, the tensile strength and compressive strengthresults for Nalco 64114 (i.e., a glyoxylated polyacrylamide polymer), anestablished commercial strength agent, are provided for comparison.

As demonstrated by FIGS. 2 and 3, Polymer 2 and Polymer 3 exhibitsatisfactory strength properties, outperforming the standard, Nalco64114 (i.e., a glyoxylated polyacrylamide polymer) (control), in bothtensile strength and compressive strength.

Example 11

This example demonstrates the effect on paper dry strength exhibited bya sheet of paper treated with a powder comprising associativelynetworked polymer(s) via an associative monomer unit and a surfactant.

Polymer 1 (control, prepared according to Example 1) and Polymer 2(prepared according to Example 2) were dissolved in water and dosed atvarious concentrations into a cellulose fiber slurry. The treated fiberswere then added to a handsheet mold and drained through a screen to forma wet fiber pad. The pad was couched from the screen, pressed, and driedto yield the finished paper sheet. The sheet was tested for tensilestrength and the results set forth in FIG. 4.

As demonstrated by FIG. 4, Polymer 2 exhibited improved tensile strengthrelative to low molecular weight Polymer 1 (control), which lackednetworking via an associative monomer unit.

All references, including publications, patent applications, andpatents, cited herein are hereby incorporated by reference to the sameextent as if each reference were individually and specifically indicatedto be incorporated by reference and were set forth in its entiretyherein.

The use of the terms “a” and “an” and “the” and “at least one” andsimilar referents in the context of describing the invention (especiallyin the context of the following claims) are to be construed to coverboth the singular and the plural, unless otherwise indicated herein orclearly contradicted by context. The use of the term “at least one”followed by a list of one or more items (for example, “at least one of Aand B”) is to be construed to mean one item selected from the listeditems (A or B) or any combination of two or more of the listed items (Aand B), unless otherwise indicated herein or clearly contradicted bycontext. The terms “comprising,” “having,” “including,” and “containing”are to be construed as open-ended terms (i.e., meaning “including, butnot limited to,”) unless otherwise noted. Recitation of ranges of valuesherein are merely intended to serve as a shorthand method of referringindividually to each separate value falling within the range, unlessotherwise indicated herein, and each separate value is incorporated intothe specification as if it were individually recited herein. All methodsdescribed herein can be performed in any suitable order unless otherwiseindicated herein or otherwise clearly contradicted by context. The useof any and all examples, or exemplary language (e.g., “such as”)provided herein, is intended merely to better illuminate the inventionand does not pose a limitation on the scope of the invention unlessotherwise claimed. No language in the specification should be construedas indicating any non-claimed element as essential to the practice ofthe invention.

Preferred embodiments of this invention are described herein, includingthe best mode known to the inventors for carrying out the invention.Variations of those preferred embodiments may become apparent to thoseof ordinary skill in the art upon reading the foregoing description. Theinventors expect skilled artisans to employ such variations asappropriate, and the inventors intend for the invention to be practicedotherwise than as specifically described herein. Accordingly, thisinvention includes all modifications and equivalents of the subjectmatter recited in the claims appended hereto as permitted by applicablelaw. Moreover, any combination of the above-described elements in allpossible variations thereof is encompassed by the invention unlessotherwise indicated herein or otherwise clearly contradicted by context.

The invention claimed is:
 1. A powder, comprising: one or moreassociative polymer(s) comprising one or more associative monomerunit(s) and one or more additional monomer unit(s) selected from atleast one of a cationic monomer unit, an anionic monomer unit, anonionic monomer unit, a zwitterionic monomer unit, or a combinationthereof, and one or more surfactant(s), wherein the one or moreassociative polymer(s) have a weight average molecular weight of fromabout 10 kDa to about 2,000 kDa, and wherein at least one of the one ormore associative monomer units is derived from a monomer of Formula II:

wherein R₃ is H or C₁-C₁₀ alkyl, X is O or NH, n is an integer from 1 to100, o is an integer from 0 to 100, m is at least 5, each Y₁ and Y₂ areindependently H or C₁-C₄ alkyl, and R₄ is H or a hydrophobic group. 2.The powder of claim 1, wherein the additional monomer unit is derivedfrom a monomer selected from a monomer of Formula I:

wherein R₁ is H or C₁-C₄ alkyl and each R₂ is independently H or anorganic group; 2-(dimethylamino)ethyl acrylate (“DMAEA”),2-(dimethylamino)ethyl methacrylate (“DMAEM”), 3-(dimethylamino)propylmethacrylamide (“DMAPMA”), 3-(dimethylamino)propyl acrylamide (“DMAPA”),3-methacrylamidopropyl-trimethyl-ammonium chloride (“MAPTAC”),3-acrylamidopropyl-trimethyl-ammonium chloride (“APTAC”), N-vinylpyrrolidone (“NVP”), N-vinyl acetamide, hydroxyethyl methacrylate,hydroxyethyl acrylate, diallyldimethylammonium chloride (“DADMAC”),diallylamine, vinylformamide,2-(acryloyloxy)-N,N,N-trimethylethanaminium chloride (“DMAEA.MCQ”),2-(methacryloyloxy)-N,N,N-trimethylethanaminium chloride (“DMAEM.MCQ”),N,N-dimethylaminoethyl acrylate benzyl chloride (“DMAEA.BCQ”),N,N-dimethylaminoethyl methacrylate benzyl chloride (“DMAEM.BCQ”),2-acrylamido-2-methylpropane sulfonic acid (“AMPS”),2-acrylamido-2-methylbutane sulfonic acid (“AMBS”),[2-methyl-2-[(1-oxo-2-propenyl)amino]propyl]-phosphonic acid,methacrylic acid, acrylic acid; salts thereof, and combinations thereof.3. The powder of claim 1, wherein the additional monomer unit is derivedfrom a monomer of Formula I:

wherein R₁ is H or C₁-C₄ alkyl and each R₂ is independently H or anorganic group.
 4. The powder of claim 1, wherein the additional monomerunit is derived from a monomer selected from 2-(dimethylamino)ethylacrylate (“DMAEA”), 2-(dimethylamino)ethyl methacrylate (“DMAEM”),3-(dimethylamino)propyl methacrylamide (“DMAPMA”),3-(dimethylamino)propyl acrylamide (“DMAPA”),3-methacrylamidopropyl-trimethyl-ammonium chloride (“MAPTAC”),3-acrylamidopropyl-trimethyl-ammonium chloride (“APTAC”), N-vinylpyrrolidone (“NVP”), N-vinyl acetamide, hydroxyethyl methacrylate,hydroxyethyl acrylate, diallyldimethylammonium chloride (“DADMAC”),diallylamine, vinylformamide,2-(acryloyloxy)-N,N,N-trimethylethanaminium chloride (“DMAEA.MCQ”),2-(methacryloyloxy)-N,N,N-trimethylethanaminium chloride (“DMAEM.MCQ”),N,N-dimethylaminoethyl acrylate benzyl chloride (“DMAEA.BCQ”),N,N-dimethylaminoethyl methacrylate benzyl chloride (“DMAEM.BCQ”),2-acrylamido-2-methylpropane sulfonic acid (“AMPS”),2-acrylamido-2-methylbutane sulfonic acid (“AMBS”),[2-methyl-2-[(1-oxo-2-propenyl)amino]propyl]-phosphonic acid,methacrylic acid, acrylic acid; salts thereof; and combinations thereof.5. The powder of claim 1, wherein the surfactant is a nonionicsurfactant of formula XII

wherein g is an integer ranging from about 12 to about 50; i is 0, R₁₂is H, and h is an integer ranging from about 10 to about
 100. 6. Thepowder of claim 1, wherein the one or more associative polymer(s)comprises a sum total from about 0.005 mol % to about 10 mol % of theone or more associative monomer unit(s).
 7. The powder of claim 1,wherein the one or more associative polymer(s) comprises a sum totalfrom about 90 mol % to about 99.995 mol % of the one or more additionalmonomer unit(s).
 8. The powder of claim 1, wherein the powder, at amedian particle size of at least 300 microns, is completely soluble asup to a 1 wt. % solution in water with stirring by a cage stirrer at 400rpm within one hour at room temperature.
 9. The powder of claim 1,wherein the powder has an intrinsic viscosity of from about 0.05 dL/g toabout 7 dL/g.
 10. The powder of claim 1, wherein the powder has aHuggins constant of from about 0.3 to about
 10. 11. The powder of claim1, wherein the surfactant is HO(C₂H₄O)₁₀₁(C₃H₆O)₅₆(C₂H₄O)₁₀₁H,polyethoxy (25) lauryl alcohol, polyethoxy (25) cetyl alcohol,polyethoxy (25) stearyl alcohol, polyethoxy (25) behenyl alcohol, or anycombination thereof.
 12. The powder of claim 1, wherein the powdercomprises a sum total of about 0.001 wt. % to about 20 wt. % of the oneor more surfactants.
 13. The powder of claim 1, wherein the powder has amoisture content from about 0 wt. % to about 30 wt. %.